1.3 sensors install in name plate and detect obstacle distance when reversing;                                                                                   2.Buzzer alarm by 3-step bi-bi sound 
3.DIY install,Only buzzer without display                                                                                                                                              4.Detection range: 2.0m to 0.3m acoustic signal increases in frequency
5.The plate size:550mm*140mm
6.Alarm volume:65dB,Work temperature: -40°C~+80°C
7.sensors can add waterproof connector,easy to replace when defective