LNDTG
If a motorized gate, door, or barrier arm hits an object (such as your car) while moving, the Linear Delta-3 Safety Edge Transmitter can automatically stop or reverse motion in order to prevent damage or injury. The transmitter wires into a Safety Edge Sensor (sold separately), which mounts on the gate/door. When the sensor detects an object hitting it, the transmitter signals the receiver.
Note: Requires a Safety Edge Sensor and a Delta-3 receiver, sold separately.