The Johnson Controls A421GEF-02C Electronic Temperature Control is a versatile temperature controller designed for HVAC and refrigeration applications, supporting 100V and 24 VAC power with a U1 input type. It monitors temperature through a compatible sensor and switches connected equipment to maintain the desired setpoint. Commonly used with air conditioners, refrigeration systems, c... https://www.partshnc.com/johnson-a421gef-02c-electronic-temperature-control-100v-24-vac-u1-type-ip66-4x