Babaco manufacturers these door sensors to insure reliabilty and eliminate false events.
The sensor is protected by a metal casting designed to be run over, banged into and abused in every way possible as trucks are loaded and unloaded.
The sensor is sized to eliminate false open events caused by the body racking under extreme conditions like when a vehicle hits a bad pothole.
These sensors are not cheap but neither is replacing a broken one.
These sensors can be configured to break ground or a closed loop.