Low-profile, flattop-mounted backup sights deploy instantly at the touch of a finger to provide relief sighting in fluid tactical situations. Drawing on their extensive manufacturing experience with high-grade, reinforced molded polymer technology, Magpul’s engineering team designed the versatile Magpul Back-Up Sight (MBUS) system to be robust, reliable, lightweight, easy to use, and affordable. Streamlined contours mean there’s nothing to snag on brush, sling, or other gear when the MBUS is folded. Spring-loaded ambi release mechanism lets you hit the grooved tab on either side, and the sight deploys and locks in place. Hit the same tabs to retract when you’re done