Detailed description of the product：

Specifications:
1 Measuring the distance by radar
2 Alarm by three step Bi-Bi sound 
3 4 front sensors and 4 rear sensors are available
4 Full-weather design, un-affected by wind, ice, snow & rain
5 All kinds of sensor colors and styles are available
6 High quality and easy to install

Technical Parameters:
Rated Voltage: 12V DC
Operating Range: 10.5V～ 16V DC
Rated Current: 50mA～ 180mA
Rear Detecting Distance: 0.3～ 2.0m
Front detecting distance: 0.3-1.0m
Ultrasonic Frequency: 40KHz
Display Working Temperature: -30 ～ +70℃

 Detail Instruction:
1.power supply: Reversing light for rear sensor
                Braking light for front sensor
                Ignition power to main box
                Gnd to Gnd
2.working detail: when begin driving, the ignition power is on, the main box is on. But if there are not any braking and reversing, the display not working.
when reversing the car, the rear 4 sensor are working, the detection range is 0.3m-2.0m
when braking the car, the front 2 or 4 sensor are working, the detection range is 0.3m-1.0m. when braking light off, the system will still working 20 second delay, so you can see 20 second display.
when braking and the reversing are working at the same time, only rear sensor working, the rear sensor is priority