4 reverse parking sensors, control unit, speaker - set

Compatible 25mm ultrasonic sensors, 4-sensor parking sensor set with control unit and speaker, which emits an audible signal that increases in frequency as the distance to the obstacle decreases. The speaker sounds faster as the car gets closer to the obstacle. The sensors are black but can be painted in any color. The sensors activate automatically when reverse gear is engaged. They assist in the parking process. The operating principle is based on ultrasonic waves, which, after bouncing off an obstacle, return to the sensor. The distance from the obstacle is indicated by the sound emitted at progressively shorter distances.