Warnex 40mm Mounts M825/825M Warnex 40mm Mounts, Maxima 2Piece Steel Weaver Stylex 40mm Base, Ruger American Rimfire, 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