Stand Alone Surge Protection Device With Isolator FuseBox F2MSPD1 100A main switch incomer T1 Surge Protection Device (SPD). Suitable for TN, TNC-S, TNC and TT systems Standard Din Rail 25mm ; 32mm knockouts top and bottom The FuseBox F2MSPD1 is is a standalone Type 1 surge protection. It can be installed inline with any manufacturers consumer unit to ensure compliance with 18th Edition regulations regarding both overload and surge protection. FuseBox manufactures a range of high quality domestic circuit protection. This includes main switch, dual RCD, electric vehicle and isolation consumer units along with a range of devices such as RCBOs, MCBs, AFDDs and accessories. . Brand FuseBox Category Surge Protection SPDs Suitable For TN/TNC-S/TNC and TT Earthing Number of Poles Single Pole and Neutral Type 1