According to the action type of contacts, the bimetal thermostat can be divided into creep action and snap action thermostat. General speaking, creep action thermostat can only be used for heating pad or cushion. Our WAA2 series thermostat belongs to creep action type.The function of creep action thermostat is for temperature adjustment, not for heating or over temperature protection. Only USA and Canada accept this kind of temperature controlling device. In Europe,creep action thermostat is not allowed to use. On the contrary, most of bimetal thermostats are snap action. The main purpose is over heat protection. Our KW model is snap action.