This is a Single-Operation-Device (SOD) for over-heat protection. When ambient temperature reaches the reset value, bi-metal in the device opens the electrical contact instantly.
This serves as the thermo cut-out to shuts off the power quickly.
This SOD reacts to ambient temperature more precisely than regular thermo-cut-out which relies on melting of solder pad. Bi-metal in the device does not limited by any holding temperature Th or Maximum Temperature Tm.
Can be more widely and reliable to apply on many electrical appliance such as steam iron, deep-fryer, skillet, grill, waffle-maker.