LiftMaster OEM Factory Direct, 377 lm (377LM) Security + rolling code technology assures a new code is sent every time the keypad is used Temporary password option enables friends or service people to enter the garage without giving them Completely wireless - powered by one 9-volt battery (included), weatherproof flip-up protective cover Works only on 315 MHz frequency and they must have a purple learn button on motor head Backlit keypad makes numbers easy to see, even in the dark, one-button-to-close feature makes it easy