Redirects high-energy transients on the mains supply lines harmlessly to earth and away from associated equipment and operators. Resets automatically. Dissipates incoming and outgoing transients. Separate mains ON and mains protection intact indication. Three separate mains protection devices between L-N, L-E, N-E with thermal overload protection. 2 metre cable length with BS1363 plug fitted. Separate neon indication to denote: (1) Surge protection is intact, (2) Supply is present.