Magpul Industries, MBUS Back-Up Rear Sight Gen 2, Fits Picatinny Rails, Flip Up, Black MFG# MAG248-BLK UPC#873750004358

The MBUS (Magpul Back-Up Sight) is a low-cost, color injection molded, folding back-up sight. The dual aperture MBUS Rear Sight is adjustable for windage and fits most 1913 Picatinny rail-equipped weapons, but is specifically tailored to the AR15/M16 platform.