Knightsbridge Screwless Telephone Master Socket - Black Nickel

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
- Minimum mounting box depth: 25mm