Surface Patress Socket Box 1 gang Size: 16mm Powermaster 1 Gang 16Mm Surface Patress Socket Box | 1435-12 The Powermaster Pattress Box - 16mm 1 Gang is a standard white bakelite box. It is surface mounted. It is for use with single switches such as a 1 gang 1 way switch, as it is the shallowest surface mounted box. The pack contains one 1 gang pattress box and has hassle free, easy to open polyurethane packaging. It requires standard installation tools and should only be installed by a competent, qualified person. It conforms to BS standard 5733.