It is close until the surface reaches 160 Celsius degree and then the switch open. Automatically reset. General-purpose low cost, compact, large capacity, minute current thermostat. This Ksd301 thermostat is used widely for coffee Maker, water heater, immersion heaters, electric cookers, microwave ovens, automatic toasters, etc. Ceramic insulator material design can provide better protection. When the surface cools off about 5 Degrees, the switch automatically close.