The Packard PF42440 Control Transformer is a reliable electrical component designed to step down high-voltage power from 120 or 208–240 volts to a safe 24-volt secondary output for HVAC control circuits. It operates by converting incoming line voltage into low-voltage power required by thermostats, relays, and control boards. This transformer is commonly used in furnaces, air handlers... https://www.partshnc.com/pf42440-packard-120208-240-24vout-40va