This heavy duty trailer link is for use on HGV where the signal from 2 cameras mounted on the trailer need to be linked to the monitor in the cab. It uses our standard 4 pin connectors and matches all our 4 pin cables. You add the length of cables required to each socket. The coil is 0.7m and stretches easily to 3m. This is the latest version of the cable which now has 2 shielded cores running through the coil. This ensures there is no "cross talk" betwee the 2 channels improving the picture quality.