Back boxes are used behind faceplates, they allow the face plates to be screwed and secured flush to a wall. Common face plates which may be used with a back box are light switches, plug sockets, modular systems, etc.
eBay
EIOMR Israel USB Type-C Power Socket Switch Combination, Black Crystal Glass Panel for Israeli Home Single Double Triple Socket
Aliexpress UK
TWIN / Double surface 25MM deep socket box. Matching curved corners on socket and back box.
eBay
EU Plug AC Outlet Power Strip USB Socket Adapter Double Socket With 2 USB Port Fast Charging Home Office Surge Protector Adapter
Aliexpress UK
Single to Double 13A Socket Converter And Socket. CONVERTS A SINGLE FLUSH MOUNTED SOCKET INTO A DOUBLE SURFACE MOUNTED SOCKET.
eBay
BSEED EU Wall Plastic Panel With Double Internet Socket CAT5 RJ45 ST TV USB Function Parts Power Socket DIY Free Combination
Aliexpress UK
• All boxes have adequate cable entries for wiring purpose (35 & 47mm have both 20 & 25mm knockouts). Material: Steel Finish: Pre coated bright galvanized steel.
eBay
BSEED PC Matte Socket Frames RJ45 CAT5 TV Satellite Type-c Double USB Sockets Wall Button Switch Function Parts Free Combinatio
Aliexpress UK
Plastic Double Dry Lining Plasterboard Wall Box 35mm. Suitable for timber and plasterboard walls. Appleby plastic double dry lining wall box 35mm suitable for timber and plasterboard walls - these are fitted into the wall (not surface mounted).
eBay
Delviz Double Power Socket, Tempered Crystal Glass Panel, USB charging interface, 146mm x 86mm, EU standard Wall Embedded socket
Aliexpress UK
3 knockout cable entries (1 at rear 2 at each side ). Dry lining box that is ideal for flush mounting in partition walls. Wall Back boxes are used behind face plates, they allow the face plates to be screwed and secured flush to a wall.
eBay
10Pcs FPC Connector Flat Flexible Cable Socket 2.54mm Pitch Film Socket Straight Pin or Bent Pin foot Double-Sided Connection
Aliexpress UK
1 Gang Single Black Surface Pattress Back Box 32mm Deep. 2 Gang Double Black Surface Pattress Back Box 32mm Deep. The BG Screwless matt black range has low profile clip on covers which sit flush against the wall ideal for modern interiors.
eBay
BSEED 1/2Gang Mechanical Button Switch With LED 1Way Single EU Power Socket Double Outlets Triple Electric Sockets Plastic Panel
Aliexpress UK
Double Wall Mounted Pattress. - Knockout cable entries & earth fixing connection.
eBay
EU 2M extension cord, type C European double socket, male plug to female socket power cord, suitable for household appliances
Aliexpress UK