The MBUS (Magpul Back-Up Sight) is a low-cost, polymer, color injection molded folding back-up sight. The MBUS Front Sight is adjustable for elevation and fits most 1913 Picatinny-railed hand guards, but is specifically tailored to the AR15/M16 platform. Spring-loaded flip up sight easily activated from either side or by pressing the top release. Protective wings shi