Napoer Car Parking Sensors Reverse Radar System with Human Voice Alert 8 Parking Sensors Black Provide 8 sensitive ultrasonic sensors, ensures your traffic security omnibearingly Real people voice with English speech alerts you section by section according different distance, closer the distance is, the alarm sound is shorter and rapider. Accuracy of obstacle distance can reach to centimeter. Self-inspection system can automatically check abnormal condition itself, avoiding reversing collision due to damaged sensors. Wide compatibility for cars,vans, trucks and so on.