The Combat Fixed Rear sight is compatible with your AR-15, M4, M16, uses Standard A2 rear sight. It is constructed of billet 6061-T6 aluminum, is Mil-Spec height, and has a black hardcoat anodized finish. 0.5 MOA Windage Adjustment for Rifle length systems. 0.65 MOA Windage Adjustment for Carbine length systems. Torque clamp to 35 in/pounds. Made in the U.S.A.