The Midwest Industries Combat Flip-Up Rear Sight is constructed of phosphate finished ordnance grade steel with a hard coated 6061 aluminum base. It features a super low profile .388" centerline when folded down and an intermediate aperture for long-range precision and close-range rapid engagement. Dual locking detent springs for added reliability and crisp positioning as well as rifle .5 MOA and carbine .65 MOA click adjustments.