4 Channel access master featuring rolling code technology and security + One ""LEARN"" channel to activate shared Liftmaster radio-controlled devices. Two five year lithium batteries included (3 volts) 390 MHZ Frequency, over 100 billion codes with code rotating technology Visor clip and Lithium battery (5 years life w/normal use) included Compatible with ALL Security+ systems, including Chamberlain, Sears, Craftsman and Raynor code rolling residential openers (Safety Signal)