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. Low or medium height Matte Black finish. (mounts) Bases for many popular rifle models available. (mounts) Forged and Machined steel construction. Versatile, available for many different rifles. Windage Adjustable (STD Mounts) Long Range STD (STD Mounts) Maximum Accessability (2 pc. Mounts) 2 Piece Bases (Mounts) STD Rings