The TKE electronic low voltage, Class 2 control gives a significant advance in sauna accuracy, convenience, and safety. Control sauna heater on-time and room temperature. Mounts outside the sauna room. Note this is the low voltage keypad that connects via 18/4 wire to the contactor box and temperature sensor in the sauna. A separate contactor box is required to turn the high voltage power on and off. This contactor box will be built to match the size ( ie. 6kW, 7.5kW, 12kW, etc) of your heater. This low voltage keypad is generic to all sauna heater sizes.