Magpul MBUS Gen 2 Rear Flip-up Sight - MAG248-BLK

Magpul MBUS Gen 2 Rear Flip-up Sight MAG248-BLK. Rear sight clamp-on folding back-up sight for flat-top AR-15 rifles. The MBUS Gen 2 is a low-cost, polymer injection molded folding back-up sight. Dual aperture, windage adjustable. Clamps to MIL-STD-1913 Picatinny/STANAG 4694 receiver rail and provides the same height-over-bore as standard irons. Sight can be folded with either large or small aperture. Spring-loaded flip-up mechanism; detent and spring pressure keep sight erect but allow unobstructed folding. Made in the USA.