Ulincos Reversing Parking Sensor LED Display U5801 Rearview Mirror Displayed Vehicle Rear Parking Assist System with 4 Sensors (Black) Car rear parking assist system as well as rearview mirror, the distance will be displayed on the top of the rearview mirror Three Colors LED digital display shows the distance between the car and obstacle High-volume warning buzzer with ON/OFF key, closer the distance the alarm sound is shorter and rapider Prevent costly collisions and help to increase safety for passengers, pedestrians and your family Enhanced CPU and advanced 4 auto detector sensors. 4 sensors are anti-freeze, waterproof, and quakeproof