The parking sensor will work automatically after the gear on the R range 4 levels of Bi-bi warnings to indicate different distance 4/8 sensors optional Accurate digital display showing distance to obstacle when reversing Different colors of sensor are available to match the car body perfect All weather detection, water and rust proof, operate in various environment Wireless display Detecting range: 0.1m-1.5m Temperature: -40--80 Voltage: DC 10V15V Power: 4W (max)