The Magpul MBUS Gen 2 Flip-Up Sights for the AR-15 continue the Magpul tradition of innovative and extremely high quality products. New features on the Gen 2 sights are a reduced size, greater optics compatibility and a spring-locking front sight post. 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. Elevation adjustment tool included, but most aftermarket A2 front sight adjustment tools may be used as well. MBUS Front Sights can NOT be mounted to a railed gas block due to excess heat issues.