This video transceiver allows you to connect 4 coax BNC video signals from CCTV cameras to a signal that can be transmitted with a single Cat 5 RJ45 cable up to 1, 000 ft. 2-transmitters are needed per installation. One attaches to the BNC video outputs of the security cameras and the other connects to the video inputs on the surveillance DVR or video recorder. RJ45 Cat-5 cable is attached between the two units. Save time and money running one cat-5 cable instead of RG59.