Universal Coaxial Receiver with Security+® - 390MHzAlso known as: 012381964123, 412HMC External 8' whip antenna included Security+ rolling code technology and or billion code DIP switch compatibility 12VDC or 18 35VAC DC jumper selectable Momentary or constant contact, jumper selection 2 piece aluminum case with detachable cover High security memory stores up to 15 Security+ remote control or keyless entry codes Normal security memory stores up to 31 LiftMaster remote control codes of any type FCC