This is a device that gives you the ability to maintain full control at all times while also having excellent "feel" when on rope. A lever-activated cam is used to control the rate of descent from rapid or long distances at a quick pace to slow for precise work positioning; either way, you are always in control. Release the lever at any time while in descent and it will automatically come to a full stop. The Spyder may be used as a belay device and is designed for use with a wide range of rope diameters.