In most cases these sights utilize dovetail or existing screws on top of the receiver for installation. They are made from an aluminum alloy that is stronger than many steels. Light, rustproof. Williams quality throughout. Fits Ruger 10/22 without drilling or tapping. A higher front sight is normally required usually .570. Also, Winchester 1300 and 1400 Slug Hunter. Features: Compact low profile Lightweight, strong, rustproof Positive windage and elevation locks Peep sight picture 3.348 inches ID