D-2001-2A/4A Car Backward Distance Sensing system consist of sensor, central control processor, and display panel. They keep strict quality control on all their products. They can solve many kind of the problems for towards narrow roads when parking their car in many countries, this is a safety warning system that alerts a driver to the distance between the rear of the vehicle and any object in the path of the reversing vehicle.
You can select different number of sensor according to your requests (2 sensors 4 sensors). Read carefully this operating manual before you use this products