FOR THE DESCENT: A lightweight, aluminum descender designed to make rappelling easy. OPTIMIZED SHAPE: Square shape to reduce twisting of the ropes while rappelling and formation of a girth hitch. Small hole can be used with thin ropes if necessary, or as a belay plate. LIGHTWEIGHT: 3.5 oz carry weight adds almost nothing to your gear rack. COMPATIBILITY: Works with single ropes 8-13 mm in diameter.