Machined steel construction. Versatile, available for many different rifles. Forward part of the base accepts a dovetail ring, locking it solidly into position. Rear ring is secured by windage adjustment screws. Long Range STD¿ mounts provide a 20-MOA slope of built-in elevation compensating for bullet drop at extreme ranges. STD 2-Piece bases offer maximum accessibility to the breech area of your rifle. STD 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. Low and Medium STD rings available in Gun Metal Gray finish..