This SKS Scope Mount is investment-cast out of 4140 steel and blued to match the gun's finish. Mount is raised to allow the shooter to use open sights as well as a scope. Notes: Raised to allow use of iron sightsGunsmithing required: Includes (4) 8-40 thread screws, receiver must be drilled and tapped in order to attach the mount. Mounting hole spacing is 3" center to center between the outer holes and 2" center to center between the inner mounting holes.