"Direct-burial Gate Opening Sensor wires directly to the Gate Opener Control Box and senses mass metal in motion. This unit is recommended for use on the inside of the property for handsfree exit by automobiles without having to push a button. Includes a 50ft. cable that should be trenched and placed next to your drive and buried no more than 12 inches deep and no closer than 30 feet from the gate. It will detect vehicles cars, trucks, ATVs, motorcycles, etc. as they cross over the sensor's 12ft. magnetic field, automatically opening the gate. Application Gate sensor. Automatically signals the gate to open when a metal object disturbs the magnetic field around the sensor Sensor has 12ft. radius Includes 50ft. cable Compatible with all GTO/Mighty Mule gate openers"