Leupold STD 30mm High 2 Piece Ring Set - Matte Black STD rings are precision engineered to match up with STD 1-piece or STD 2-piece bases. Rear ring is secured by windage adjustment screws. Available in five different ring heights. Machined steel construction. Features: Forged and Machined steel construction Versatile, and available for many different rifles Windage Adjustable (STD Mounts) - The forward part of the base accepts a dovetail ring, locking it solidly into position. The rear ring is secured by windage adjustment screws Long Range STD mounts provide a 15-MOA slope of built-in elevation compensating for bullet drop at extreme ranges Maximum Accessability - 2-Piece bases offer maximum accessibility to the breech area of your rifle 2 Piece Bases - 2-Piece bases fit right and left-hand actions, and reversible bases are available for many actions STD Rings are engineered to match up with STD 1-Piece and STD 2-Piece bases. Five different ring heights are available for STD bases