This is a 4 way medium duty trailer link for use with our cameras that have the 4 pin connectors. It is ideal for caravans and trailers where you need two or more cameras. They carry both power and video to the cameras. When connected they are fully waterproof and there are water resistant covers on the sockets when not in use. The coil needs to be stored in a clean and dry environment when not in use. The coil is approximately 0.8m and extends to almost 2.0m.