Maxima M858/918 Fits Ruger 10/22 Maxima Bases - The 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. - Low profile design allows use of iron sights when optics are removed. - Full width and depth recoil slots provide maximum bearing surface for recoil key engagement. - Bases securely mount to your firearm with Torx-style T-15 socket cap screws 25 in/lb. of torque is recommended.