Make of metal, it has high temperature resistance and resistance, ensuring a long service life This switches, with excellent sensitivity and precisely, can achieve temperature detection and timely Easy installation: Simply use basic tools ( not included) to remove the old switches, then install the limit switches face up and connecting the wires correctly The manual reset design enhances both and equipment maintainability Specially designed for furnaces fan systems, this furnaces temperature limiter will automatically disconnect its contacts when the temperature rises to 250℉, effectively overheating and maintaining normal operate of the furnaces body