When the ambient temperature is lower than the temperature set by the thermostat, the circuit close and the heater equipment starts. When the ambient temperature is higher than the temperature set by the thermostat, the circuit is disconnected and the heater equipment stops The bottom of KTS011 mechanical temperature controller switch is with 2 wire interfaces,which can make wire connection become more sturdy The mechanical thermostat temperature controlling range is from 0Celsius to 60Celsius, perfect for using to control heater.The adjustable button is for easy and convenient to adjust the controlling temperature The mechanical temperature control switch mainly use for controlling heating applications, Weight: 0.10802650838 Pounds, Manufacturer: Jaywool