The MBUS from Magpul is a low-cost color-injection molded folding backup sight.The dual aperture MBUS Rear Sight is adjustable for windage and fits most 1913 Picatinny rail-equipped weapons but is specifically designed for the AR15 / M16 platform.The spring-loaded flip-up sight is quickly activated from either side or by just pressing the top.Magpul MBUS Rear Flip-Up SightPolymer Black FinishFits Most 1913 Picatinny Rail-Equipped WeaponsAll Needed Mounting Hardware is IncludedAdditionally this rear sight clamps to MIL-STD-1913 Picatinny/STANAG 4694 receiver rail and provides the same height-over-bore as standard A2 irons.Order your rear flip-up sights online today!Score big savings and fast shipping when you shop our large selection of cheap bulk .223/5.56 ammo for sale.Looking for more AR-15 magazines? Get big savings when on our entire online inventory of low-priced AR15 Mags for sale