The 12V DC Power Relay Filter Rectifier can used to supply the stabilized 12V DC power to the rear camera.for Germany/American Car Series Note: Please do not purchase if your car is non-German or American Car Series, because there is different currents for different car series, non-pulsed signal interference, use this filter line is invalid Without DC Plug With DC Plug Function Car Rear View Rectifier can effectively to supply the stabilized 12V DC power to your rear camera, help to solve the issue of the "screen cyclowarp" or "black screen" when using a rear camera reversing. Professional Camera Rectifier with high characteristic and stable performance Wire Setup: Input Red Wire: Reversing Light Positive Pole Input Black Wire: Reversing Light Negative Pole Output Red Wire: Camera Positive Pole Output Black Wire: Camera Negative Pole Why do need Power Filters Reversing? because Some models of German cars and American cars will output voltage interference after the engine is started. The power supply to the reversing light is not pure DC power supply, but a pulse signal is superimposed on top oscilloscope can be used to test if the conditions will it found a similar squarewave signal. Camera power supply line directly on the reversing light, because the working voltage is very unstable cause the camera does not work properly, the video signal output is also not normal, so the host can see there is a severe interference, jitter, or not to switch reversing screen. Package Included: 1 * Car Rear View Rectifier