The ISC D4 Work/Rescue Descender features a unique and innovative cam action, which offers precise control at slow or fast speeds. The progressive cam works by way of one cam operating inside another cam. The D4 has a 240kg (500lbs) Working load limit - suitable for two-man rescue, without the need for the creation of extra friction. The handle mechanism is designed to rotate through 360º making it easier and simpler to use. The handle itself is made from aluminum rather than plastic and is coated in a specially chosen paint which provides extra grip. Cleverly, the handle rotation is accompanied by audible clicks which help the user identify the correct position of the handle. Similar to the Petzl RIG in usage and design but with the added benefit of an anti-panic feature. Can be used as a single line descender, base anchor for access lines, as a progress capture and descender in rescue hauling situations....