Mighty Mule Mm136 Wireless Keypad IntercomMighty Mule Wireless Keypad & Intercom System The Mighty Mule MM136 Wireless Keypad Intercom enables secure property access and communication up to 500 feet away. Designed for convenience, it integrates a programmable keypad with a reliable intercom system that operates even during power outages, thanks to its rechargeable batteries. Key Features: Security & Convenience: Easily screen visitors and manage property access from indoors with an intercom