Mighty Mule Wireless Digital Keypad (FM137) Wireless weatherproof keypad. Numeric keypad for controlled access with simple programming that can hold up to 25 access codes. Additionally, you can have temporary codes that can be programmed to expire within one to seven days. The Mighty Mule Digital Keypad is designed to work with all Mighty Mule Automatic Gate Openers; this is an ideal accessory for convenience and security. Easy DIY (Do It Yourself) programming for your Mighty Mule Automatic Gate Opener system. Backed by a 12 month Mighty Mule Warranty and Technical Support.