The Warne Maxima Steel Bases are modeled around the popular Weaver design, which is one of the strongest and most versatile mounting systems available today. The low profile of the Maxima Steel Bases give your firearm a sleek look. When used in conjunction with Warne Maxima QD Rings, the shooter is able to utilize the open sights by looking over the top of the bases without sacrificing the normal shooting position behind the firearm. Maxima Bases also offer a full width recoil slot in each base. This feature allows the recoil control keys of Warne Rings to attain maximum bearing surface. Mfg: Warne Mfg. Company SPECS: 12L14 steel. Available in polished blue, matte blue, or silver. Two-piece only, Includes mounting screws. Do not mix Maxima bases with other brands of Weaver-style base, the heights are often different. RHS = Rear Hole Spacing. Fits #1 fits Browning BAR, BAR II, Mark II(TM), BLR Li