A surge protector like this one manufactured by the reputable is an appliance or device designed to protect electrical devices from voltage spikes as well as current spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or shorting to ground any unwanted voltages above a safe threshold. Specifications: Rated working voltage : AC 230V/50Hz Rated working current: 40A Maximum short circuit withstand current 3000A below 40A, 4500A above 50A (action time 10ms) Over Ampere protection value : 5-60A or  1A-40A Automatic closing delay : 0-30s, factory default 30s Action time : 0-30s , factory default 30s Own power consumption: ≤ 1.5w Motor mechanical life: ≥ 100,000 times Dimensions: 80*37*66mm (L*W*H) Working environment temperature range : -25 C – 55 C Relative humidity : 45-90% RH, 40C Altitude: ≤ 2000m Pollution level: 2 Class Package Includes: 1 x  Adjustable Ampere Over Protector Relay Breaker