Not only does this excellent reversing sensor alert you to objects or people behind your vehicle, it will give you an estimated distance to them and indication of the objects location via the dash mountable display. The system uses four ultrasonic sensors to sweep the area behind the car and provides an audible warning as you approach an unseen object. Installation is easy as the system utilises the existing reversing light cable. You do not need to connect the display monitor directly to the control box in the car's boot. The monitor display sits neatly on the dashboard and provides visual location and distance information as well as the audible distance warning.This is an excellent device and a worthwhile safety feature on any vehicle. Monitor measures 110(W) x 40(H) x 80(D)mm. Control box 110(W) x 25(H) x 73(D)mm. 18.5mm Sensor hole drill included.