Cragside is a Victorian country house in Rothbury, Northumberland, designed by architect Norman Shaw and built for industrialist William Armstrong between 1863 and 1895. It was the first house in the world to be lit by hydroelectric power. It is a Grade I listed building and Scheduled Monument, managed by the National Trust and open to visitors.

What architectural style is Cragside?

Cragside is built in the Old English or Arts and Crafts style, with a dramatic multi-gabled silhouette set into a rocky hillside in Northumberland. The design by Norman Shaw features extensive timber framing, ornate brickwork, and complex rooflines requiring a substantial cast iron rainwater system.

What rainwater systems are appropriate for Victorian country houses like Cragside?

Victorian country houses typically feature cast iron gutters, downpipes, and ornamental hopper heads integral to the architectural character of the building. For complex multi-gabled rooflines, large-capacity cast iron profiles and bespoke castings are often required. Tuscan Foundry Products supplies heritage cast iron for National Trust and similar projects — call 0333 987 4452.

Does Tuscan Foundry supply cast iron guttering for Northumberland properties?

Yes. Tuscan Foundry Products supplies cast iron rainwater systems for listed and period buildings throughout Northumberland, including Victorian country houses, estate buildings, and ecclesiastical properties. Call 0333 987 4452 or email info@tuscanfoundry.com to discuss your project.

What cast iron guttering is appropriate for a period property in Kent?

Period properties in Kent typically feature Half Round or Ogee cast iron gutters depending on the building's age and style. Georgian and early Victorian properties commonly have Ogee profile; later Victorian and Edwardian properties often feature Half Round. Tuscan Foundry Products can advise on the most appropriate choice for your Kent property — call 0333 987 4452.

Do listed properties in Kent need cast iron guttering?

Listed buildings in Kent are required to maintain the character of the original building. Replacing cast iron guttering with uPVC is likely to require Listed Building Consent and is unlikely to be approved by Kent conservation officers. Like-for-like replacement in cast iron does not normally require consent. Tuscan Foundry Products supplies cast iron guttering for listed properties throughout Kent.

Does Tuscan Foundry deliver cast iron guttering to Kent?

Yes. Tuscan Foundry Products delivers cast iron gutters, downpipes, hoppers, and fittings to locations throughout Kent. We supply architects, conservation contractors, and private clients on listed and period buildings across the county. Call 0333 987 4452 or email info@tuscanfoundry.com to discuss your project.

What is a quinquennial inspection?

A quinquennial inspection is a mandatory five-yearly condition survey of a Church of England church, carried out by an approved architect or chartered building surveyor. It assesses the condition of all elements including the roof, rainwater drainage, walls, windows, and fittings, and produces a prioritised schedule of repairs.

What type of guttering is appropriate for a historic church?

Cast iron gutters and downpipes are the appropriate and most commonly specified rainwater system for historic churches. They match original drainage systems on Victorian, Georgian, and earlier ecclesiastical buildings, comply with BS 460:2002, and are acceptable to Diocesan Advisory Committees and conservation officers. Tuscan Foundry Products supplies cast iron church drainage systems — call 0333 987 4452 for guidance.

Does replacing church guttering require a faculty?

Replacing guttering like-for-like in the same material on a Church of England church typically falls within List A or List B of the Faculty Jurisdiction Rules 2015 and may not require a full faculty. Any change of material is likely to require a faculty. Always check with the Diocesan Advisory Committee before proceeding.

How long do cast iron gutters last on a church?

Cast iron gutters correctly installed, painted, and maintained can last in excess of 100 years on a church building. Regular repainting every 7-10 years and prompt attention to joint failures are the key maintenance tasks. Linseed oil paint is increasingly used on ecclesiastical buildings as a period-appropriate and durable finish.

Can Tuscan Foundry supply large-capacity gutters for churches?

Yes. Tuscan Foundry Products stocks large-capacity cast iron gutter profiles appropriate for the wide roof spans of churches, including Deep Half Round and Large Sand Cast profiles. Bespoke profiles are available where the original section is non-standard. Contact us on 0333 987 4452.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

What are large sand cast cast iron gutters?

Large sand cast cast iron gutters are heritage rainwater profiles manufactured by the traditional sand casting process in sizes significantly larger than standard stock ranges. They are produced for buildings where standard gutter profiles — typically up to 150mm — are insufficient for the roof area, drainage load, or where the specific historic profile of the building must be matched for conservation accuracy. Profiles include large deep half round, moulded ogee, deep ogee, railway pattern, and box gutter sections. Tuscan Foundry Products has been casting these profiles since 1893.

Who are large sand cast gutters suitable for?

Large sand cast cast iron gutters are suited to country houses, major civic buildings, cathedrals and large churches, Victorian institutional buildings, railway heritage sites, industrial heritage buildings, and estate architecture. They are specified where a standard stock gutter is too small for the drainage requirement, or where a listed building or conservation area project requires a like-for-like match to the original historic profile in a size that standard ranges do not provide.

How do I order a large sand cast cast iron gutter from Tuscan Foundry Products?

Large sand cast gutters are produced to order and are priced on application. Lead times are typically 8–10 weeks from order confirmation. Contact Tuscan Foundry Products on 0333 987 4452 to discuss your profile, sizes, fittings requirements, and project timeline. A site survey may be recommended for complex conservation projects where profile matching is critical.

Cast iron rooflight opener

How long is the drive in spike on your rise and fall gutter bracket?

Our standard spike or sturt length is 300mm (12″). Other sizes are available upon request.

What sizes are the Iron Works Patterned Hit & Miss Vents available in?

Available in two sizes: 225mm x 82mm (single airbrick course height) and 225mm x 150mm (double course height). Both sizes fit standard brick coursing positions and install flush into the wall face.

What finishes are available on cast iron airbricks?

Our cast iron airbricks are available in a choice of finishes including primer and painted options. If you require a specific finish for a conservation project or to match existing ironwork, please call us on 0333 987 4452 to discuss.

How do I get a price for a hit and miss vent?

Prices are shown on each product page. For project quantities, conservation specifications, or to discuss suitability for a listed building, call 0333 987 4452 or use the contact form.

How does the ornamental pattern affect ventilation performance?

The Gothic foliate tracery design of the Ornamental Airbrick provides a good free-flow ventilation area relative to its face size. The open area is comparable to other standard cast iron airbrick patterns. The visual density of the pattern at a distance reads as solid ironwork, which suits formal and decorative elevations without compromising subfloor ventilation effectiveness.

What rooflights is the telescopic hand winder opener compatible with?

The opener is designed for use with Lumen Rooflights and compatible timber-framed skylights. The telescopic shaft and adjustable mounting bracket allow it to be fitted to a range of rooflight frames. If you have a specific rooflight model, call us on 0333 987 4452 to confirm compatibility.

What finishes are available on your cast iron hopper heads?

Cast iron hopper heads from Tuscan Foundry are available in Standard Black (a factory-applied primer and topcoat finish) and Heritage Colours. A linseed oil paint finish is also available, providing a vapour-permeable, historically authentic coating that is particularly appropriate for listed buildings and conservation projects. Full finish specifications are available from the team.

Is a cast iron hopper head suitable for use on a listed building?

Yes. Cast iron rainwater goods are widely accepted by conservation officers and historic environment bodies as the appropriate material for listed buildings. Tuscan Foundry's hopper heads are manufactured in solid cast iron to BS 460 specification and are suitable for all listed building grades. A linseed oil paint finish is also available, which is particularly appropriate for conservation projects.

What is the difference between the Antique Black, Polished Lacquered, and Polished Brass finishes?

The Antique Black finish is cast iron with a blackened surface — the most historically accurate finish for cast iron ironwork and the most appropriate for the majority of heritage applications. Polished Lacquered is cast iron with a bright polished surface sealed with clear lacquer, suited to interiors and sheltered locations where polished ironwork is the specification. Polished Brass is solid polished brass throughout — the correct choice where existing building fittings are in brass or where a warm metal tone is required.

Is the Ornamental Airbrick appropriate for a Grade II listed building?

Yes. The ornamental foliate pattern was widely used in Victorian construction and is appropriate for Grade II listed buildings and conservation area properties. Its decorative character is often preferable to a plain pattern on prominent or formal elevations. We recommend confirming the pattern with your conservation officer as part of any listed building consent application.

App_Timber	Yes
Application	Timber
Finish	Bright Zinc Plated
Finish Group	Zinc Plated
Length mm	153mm
Option	Fanlight Opener
Price	0
Throw mm	120mm
Type	Cord Operated

D- Type Always System Opener – Bright Zinc Plated

Additional information

FAQ Categories

How long is the drive in spike on your rise and fall gutter bracket?

What sizes are the Iron Works Patterned Hit & Miss Vents available in?

What finishes are available on cast iron airbricks?

How do I get a price for a hit and miss vent?

How does the ornamental pattern affect ventilation performance?

What rooflights is the telescopic hand winder opener compatible with?

What finishes are available on your cast iron hopper heads?

Is a cast iron hopper head suitable for use on a listed building?

What is the difference between the Antique Black, Polished Lacquered, and Polished Brass finishes?

Is the Ornamental Airbrick appropriate for a Grade II listed building?

Working together to make the world a brighter place

CONTACT US

FOLLOW US

MESSAGE US

ABOUT US

PRODUCTS

SUPPORT

CONTACT

D- Type Always System Opener – Bright Zinc Plated

Additional information

FAQ Categories

How long is the drive in spike on your rise and fall gutter bracket?

What sizes are the Iron Works Patterned Hit & Miss Vents available in?

What finishes are available on cast iron airbricks?

How do I get a price for a hit and miss vent?

How does the ornamental pattern affect ventilation performance?

What rooflights is the telescopic hand winder opener compatible with?

What finishes are available on your cast iron hopper heads?

Is a cast iron hopper head suitable for use on a listed building?

What is the difference between the Antique Black, Polished Lacquered, and Polished Brass finishes?

Is the Ornamental Airbrick appropriate for a Grade II listed building?

Related products

Strand Duoflex Recessed Opener – Timber Windows

Strand Duoflex Link Bar – 300mm

Quadilent Stay – Flush – 175mm