The Rawl 5-Piece sleeve bolt is a construction grade fastener that is commonly used as a climbing anchor. Expansion is created by tightening a threaded bolt wich draws a tapered cone expanding the sleeve against the walls of the hole. The Rawl 5-Piece is very well suited to soft rock types where maximum expansion is needed. Specs: Materials: Stainless Steel Diameters: 3/8" or 1/2"