4 button Key Fob uses 12V camera battery. Range is 75-70ft. Pressing either of the 2 buttons causes "Transmit" LED to light & transmission of 8 security code bits (256 codes that you set by cutting traces on board) plus Data code. Pressing any button, when received, causes: "Valid ID" relay contact to closes; a latched +5VDC on appropriate Data line. NOTE: Requires modification of unit (cut trace & add jumper) to have single output at receiver for each button pressed
