Liftmaster 423LM 390MHz 3 Channel Coaxial Gate Radio Receiver Remote Control

Activates up to three doors or gate openers or one opener that with open, stop, close function. Accepts one digital code switch code per channel. External 8" whip antenna with F-connector. 2-piece aluminum case reduces possible radio interference. Isolated dry contact output for each channel. Power: 18 - 30 volts AC or DC