The Lighthanger unit consists of a system of 2 hooks joined by a braided rope and a safety pulley.The pulley, which is attached to one of the hooks, blocks the rope constantly and only lets it run, when we press a lever.In this way, one hook remains fixed at one end of the rope and the other hook together with the pulley, you can slide along the rope giving it the desired distance.
You just have to hook one hook to a bar or fixed tube and the other hook to the device you want to hold, and with just press or release the lever, you unlock or lock (respectively) the rope.