Having a built-in thermostat, the Thermo-Cube Temperature-Controlled Outlet regulates electricity usage according to the surrounding ambient air temperature. Plugged into any standard 15-amp (120-volt rating) outlet, it turns on or off automatically any electrically powered device that's plugged into it. There are five versions of the double-receptacle outlet. Three are cold-weather ones for vehicle applications, such as engine or battery heaters) and for farm/home applications, such as stock-tank or pond de-icers, unheated rooms, pump houses, greenhouses, boats and RVs. Two are warm-weather ones for turning on/off all types of fans (e.g., window, ceiling, exhaust, ventilator, attic, roof) when certain temperatures are reached.