The reverse radar is a safety assistance device for parking or backing up, which can inform the driver of the obstacle in the situation, relieves the driver of parking, backing up and starting the vehicle, and helps the driver to eliminate of time and visual disturbances that driving safety.Usually reversing radar through the ultrasonic sensor (commonly known as the probe),Controller and display (or buzzer) and other components. The reverse radar generally uses the principle of ultrasonic distance measurement.Under the control of the controller, the ultrasonic signal is sent from the sensor.When the obstacle is encountered, the signal is generated. receipt of the signal, the sensor performs the data processing by the controller,The location of the obstacle, the ad by the display distance and issued other warning signals,receive warning so that the driver makes the back to become aware of it so that back on the road is easier.Plug and playInternal item number: 66216902180Assembly: Parking sensors ()Pins: 3 pinVehicle models: for 3 Series E46 (from 1998) / C8 / / 807Color: BlackMaterial: PlasticPackage contents:1 * Reverse radar sensorOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.