1.Display the optical image by a rearview camera equipped at car rear bumper
2.the camera diameter is 18mm,need to drill hole on the bumper;it also can be changed by the other cameras                               3.Measuring the distance by sensors,the detected distance can be 0.3-2.0m
4.The distance and rear videos are showed on the 4.3 inch LCD Monitor,which is sticked on the dashboard in car driving room.The monitor can be changed by other monitors                                                                                  

5.Alarm by three step Bi Bi sound,voice alarm is optional. 
6.sensors can add waterproof connector,easy to replace when defective