The working principle of the sensor: 8-sensor products: 4 in the rear of the car and 4 in the front of the car. When reversing, six sensors are activated, four at the rear of the car and two at the front of the car. When driving, the brakes activate the four sensors at the front of the car. monitor: 1: Display the distance of obstacles in multiple directions 2: Show the distance of the nearest obstacle. 3: Sound alarm. Features: Rate voltage: 12V DC Rate operating range: 10.5V - 16V DC Rate current: 100mA - 300mA Detecting distance: 0.3 - 2.0m Ultrasonic frequency: 40KHz Control moudle working temperature: -30 - 80 celcius degree.
eBay