635LM Sears Craftsman LiftMaster Chamberlain Security+ Universal Garage Door Opener Plug-In Receiver Compatible with all LiftMaster Security+ remote controls Plugs into standard polarized 120V, 60Hz AC outlet Includes 2-conductor bell wire Hard wires directly to any garage door opener strip Accepts up to 8 Security+ remote control codes, and accepts one 976/977LM keypad