The ISC D4 Descender features a unique and innovative cam action, which offers precise control at slow or fast speeds. It can be used to ascend, descend, lower, and capture loads in the haul system. The D4 has a 240kg (550lbs) Working Load Limit which means it is suitable for two-man rescue. The handle mechanism is designed to rotate through 360º making its use easier and simpler. And handle itself is made from aluminum rather than plastic and is coated in a specially chosen paint which provides extra grip. The handle rotation is accompanied by audible clicks which help the user identify the correct position of the handle.
Plus, the ISC D4 is the only ANSI certified descender on the market today.