The Midwest Industries Combat Fixed Rear Sight for AR-15's, M4's, and M16's is Mil-Spec height, and features a standard A2 rear sight aperture which is compatible with Trijicon replacement apertures. Made from billet machined T6 6061 aluminum and hardcoat anodized. The Combat Rear Sight has rifle 0.5 MOA and Carbine 0.65 MOA click adjustments.