1. we are not a switch will connect the wireless camera, and all products can support PAL or NTSC, But don't support PAL and NTSC at the same time. 2. Please choose a quality camera to connect. A bad camera cannot be identified by the control unit. 3. when the ACC product is on, your screen is blue, the product will work properly. 4. After installation, your camera does not work, please check the quality of your camera and your connection. Thank you. 5. Four-channel car video controller with four-door partition, with a mirror switch for each camera.You can see 4 camera images in one window<br><br>Image Sensor:1/4inch CCD TV system:NTSC(Default) or PAL Horizontal Resolution:580 TV lines Pixels:656(H) x 592(V) Sync. System:internal S/N Ratio:Greater than 48dB Night Vision:Yes Electronic Shutter:1/60 to 1/100,000 seconds Video Output:1.0Vpp, 750hm White Balance:Auto Power:DC 12V Operating Temperature:-40 to + 80 degree, 95% RH maximum Storage Temperature:-40 to + 105 degree, 95% RH maximu Video Cable Length:about 6m Colour:Black Material:Plastic+Metal Size:22.5MM<br><br>Package Contents: 1 x Camera Video Control 1 x remote control<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.