APPLICATIONS? This is an upgraded industrial grade ahd 1080P wired 2-camera system. It is compatible with most of the vehicles with a free power input range DC12-24V and supports with max 2 cameras. TVS and ESD device is built in to protect the monitor from being damaged by the transient high power of vehicles and the electro static as high as 8kv. And this monitor only supplies camera which is in use with DC12V, it saves energy. It is compatible with PAL/NTSC/AUTO. HEAVY DUTY CAMERA? It is color camera with the resolution of 1080P, provides super clear and real color image. The viewing angle is 120 degree. So it works perfectly in kinds of weathers. The monitor has three modes for option by menu to lighten the screen at day time and darken at night, not glare. Monitor has a built-in protector for protecting monitor from being damaged by power polarities reversed. With built-in innovative system previous option settings memory even after it’s turned off. Camera’s image can be set as mirror, non-mirror or up-side-down by OSD menu. Distance grid line can be turned on or off by OSD menu. Monitor will be triggered to be turned on automatically to display camera image when reversing. After reversing, the monitor will be back to the pervious mode. This system has two viewing options(view when reverse or remain on continuously). We uses waterproof Aviation 4-pin screw connectors, NO BNC/RCA. Why buttons not work? —Disconnect the trigger wire, it will work. Trigger wire needs to be connected to power of rear lamp.