Quad Splitter is a combiner to combine up to 4 cameras and to show them on a monitor screen split into 4 at the same time. Usually, it also has built-in switcher which can display the pictures one by one. Some models have BNC jacks for video inputs and others RCA jacks. You may choose one according to your camera's video connection type. But, if the video input jack is different with your camera's connection, you can get a BNC/RCA converter easily at any electronic parts shop like Radio Shack or Best Buy, etc. B/W splitter works with B/W cameras and color splitter with color cameras. A quad splitter is to be connected to a CCTV monitor, TV or VCR.