This SKS scope mount from Choate is investment cast out of 4140 Steel. Once installed you can continue to clean you SKS as normal without removing the mount. Mount has enough height to retain use of the open sights. Will require gunsmithing to install. Includes four 8-40 screws. Drill and tapping of the receiver is required. Mfg: Choate SPECS: Includes four (4) 8-40 screws. Hole spacing: 3" center-to-center between the outer mounting holes and 2" between the inner mounting holes.