Description The 50 ft. wired Driveway Vehicle Sensor (FM138) allows a vehicle to drive past the sensor's 12 ft. magnetic field and will open your gate automatically, allowing guests the ability to exit without a Remote (FM135). Works with single and dual gates. Easy DIY (Do It Yourself) installation. Can be installed 3-50 ft. away from the gate. Also available are longer lengths including the 75 ft. Vehicle Sensor (FM138-75) 100 ft.Vehicle Sensor (FM140) and 150 ft. Driveway Vehicle Sensor (FM141). Mighty Mule Wireless Driveway Vehicle Sensor (FM130) also available for wireless installation. Backed by a 12 month Mighty Mule Warranty and life time technical support.