Warnex 40mm Mounts M858/918M Warnex 40mm Mounts, Maxima 2Piece Steel Weaver Stylex 40mm Base, Ruger 10/22, Matte black 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