Many AR-15 rifles on the market are equipped with the popular A2 front-sight gas block, and this permanent fixture on the gun provides a solid opportunity for a good back-up sighting option, even for rifles equipped with red dots. Complete the sighting set by adding the all-new Midwest Industries AR-15 Combat Folding Rear Sight to your rifle. To ensure both strength and lightness, each Midwest Industries AR-15 Combat Folding Rear Sight is made from a combination of ordnance-grade steel and proven 6061 aluminum. Flipped up, the rear aperture meets military specifications for height requirement, so it'll match up easily with any standard A2. Folded down, the sight measures only .38 Mfg: Midwest Industries