Knightsbridge
Telephone Master Socket
Smoked Bronze
The master socket contain a surge arrestor and an R/C circuit filter these are used by your service provider to get a fixed value resistance when they run line checks.
Standard BT type socket with screw type terminals.
Flawless Screwless design Master BT type socket.
Screw terminals.
Screwless low profile design with built in gasket.
Certified to BS 5733.