Our Garage Door Remote Receiver Keypad is a secure wireless keyless entry system that opens or closes your garage door without the use of a remote or key. The system can open the door with a dedicated 4-digit code that is programmed directly into the unit. Replacement for 877MAX G940EV-P2 878MAX 377LM 977LM 877LM 66LM CMXZDCG440 This garage door keypad uses the latest Security+ 2.0 rolling code technology to synchronize with your existing opener frequency, eliminating radio wave interference. Rigorously tested with professional testing equipment. The garage door keypad has 3 channels connected to three openers; one keypad controls up to 3 motor units. This wireless garage door keypad is compatible with 1993 garage door remotes with purple-yellow-red-orange-green learn buttons. Does not work for 200.57933 57943 57953 Series 100 CR1150 139.57943 139.57953 Keyless entry offers wireless installation and wireless programming. Large backlit buttons provide quick and easy entry in the dark. Protective cover protects against the elements. Provides one-button closing function to easily close the garage door. Convenient Design: Backlit buttons for quick and easy entry in the dark. Protective cover protects against rain splashes. Product Name: Garage Door Opener Keypad Item Number: 877MAX Frequency: 310/315/390Mhz Code: Rolling code Battery: Built-in battery 9V carbon battery Working Voltage: 3v Working Current: less than or equal to 12mA Transmission Distance: 100 meters (open) Operation: The same as the old remote control, must be paired with the host computer Color: As Shown Material: Plastic Package Contents: 1 x Remote Control 1 x Battery 2 x Screws/Nuts