This is part of a modular system similar & compatible with the C-Line system and mainly used in leisure vehicles. Being modular , there are many options as to the fitting method, plus there is a choice of low profile or standard faceplates.This frame is suitable for fitting CBE or C-Line switches & sockets & does not require a support frame. Other frames in different styles & colours are available from our ebay shop. Suitable round or square holes are required, in most cases round 55mm or square 43mm (for each socket) would suffice, but check the actual socket before cutting! The assembly is then screwed to the wall and finally the cover is clipped into place.