{"product_id":"1-gang-25mm-galvanised-steel-back-box","title":"1 Gang 25mm Galvanised Steel Back Box","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eThe Knightsbridge GSK25 is a 1-gang galvanised steel back box with a 25mm recessed depth, designed to house switches, sockets and dimmers in residential, commercial and industrial installations. The box measures 73mm x 73mm at the face and is pressed from 1mm-thick galvanised steel, providing corrosion resistance and structural rigidity when fixed into masonry, plasterboard or dry-lining.\u003c\/p\u003e\n\u003cp\u003eThe box features one fixed mounting lug and one adjustable mounting lug, allowing the faceplate to be levelled even where the box sits slightly off-square in the wall. An integrated earth terminal provides a connection point for protective earth continuity, meeting UK wiring regulation requirements. Multiple 20mm knockouts on the sides and rear accept standard PVC conduit, flexible conduit or cable entries, giving flexibility for both surface-fed and back-fed wiring runs.\u003c\/p\u003e\n\u003cp\u003eThe 25mm depth suits installations where wall cavity space is limited, including single-skin blockwork, timber stud partitions with 12.5mm plasterboard, and retrofits into existing shallow chases. The galvanised finish protects the steel from oxidation in damp conditions during the construction phase and throughout the life of the installation. The box accepts all standard 1-gang switches, sockets and dimmers from Knightsbridge and other manufacturers using the 73mm x 73mm British Standard mounting pattern.\u003c\/p\u003e\n\u003ch5\u003eSpecification\u003c\/h5\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeight\u003c\/td\u003e\n\u003ctd\u003e73 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWidth\u003c\/td\u003e\n\u003ctd\u003e73 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecessed Depth\u003c\/td\u003e\n\u003ctd\u003e25 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConstruction\u003c\/td\u003e\n\u003ctd\u003eSteel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEarth Terminal\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch5\u003eDownloads\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/products_2795600_datasheet.pdf\" target=\"_blank\"\u003eProduct Specification Sheet\u003c\/a\u003e\u003c\/p\u003e\n\u003ch5\u003eFrequently Asked\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eWhat wall constructions suit a 25mm back box?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe 25mm depth works in single-skin blockwork, timber stud partitions with 12.5mm plasterboard, and shallow chases in solid walls where a deeper box cannot be accommodated. For dry-lining installations, ensure the plasterboard thickness plus the box depth does not exceed the available cavity space.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAre the mounting lugs adjustable?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOne lug is fixed and one is adjustable. The adjustable lug allows the faceplate to be levelled if the box is slightly off-square in the wall, which is common in retrofit installations or where the chase was cut by hand.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat size knockouts does it have?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe box has 20mm knockouts on the sides and rear, accepting standard 20mm PVC conduit, flexible conduit or grommeted cable entries. Knockouts are punched out with a screwdriver or similar tool during installation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs the earth terminal compliant with UK wiring regulations?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The integrated earth terminal provides a connection point for protective earth continuity as required by BS 7671 (the IET Wiring Regulations). The galvanised steel construction provides an effective earth path when correctly bonded.\u003c\/p\u003e","brand":"Knightsbridge","offers":[{"title":"Default Title","offer_id":45293883064587,"sku":"GSK25","price":1.49,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/177332_31374487-6f78-46e1-9cc2-326cf4b6871b.jpg?v=1714665487","url":"https:\/\/niori.co.uk\/products\/1-gang-25mm-galvanised-steel-back-box","provider":"Niori","version":"1.0","type":"link"}