The scope and the barrel become one unit to effectively cancel small shifts in zero between the receiver and the barrel for increased accuracy. Thirteen cross-slots provide a wide range of mounting positions; cantilever design centers the weight over the grip for better balance. Cutaway over the receiver allows sufficient scope height for proper functioning and ejection. Fits all factory bull barrels; Weaver-style rings. Mfg: Lsp SPECS: Aluminum, matte finish, black, anodized. 5-1/4" (13.3cm) long. Fits LSP Match Barrels; factory bull barrels require drilling and tapping. Includes instructions and screws.