Protect valuable equipment from being damaged by electrical surges & spikes Surge indicators to ensure surge protection is still active Stop spikes & surges from damaging your equipment & data. This range of sockets has a built-in visual indicator so that you can be sure that the surge protection circuit is operational. If the visual indicator goes out power could still pass through the equipment but the unit has reached its capacity for surge protection leaving equipment susceptible to subsequent spikes & damage. A new unit must be purchased to restore surge protection. Protection is afforded by 3 energy absorbing varistors connected L-N L-E & N-E. Fitted with Approx. 2m cable & mains plug.