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

Dimensions: 87.5mm x 87.5mm

IP Rating: IP20

15 year warranty