The continuous top rail allows you to mount iron sights, optics and any other accessories without additional rail sections. The KeyMod system allows users to customize the handguard with rail sections and direct mount accessories. The handguard is constructed of aircraft aluminum and finished with a Mil-Spec type III hard coat black anodizing. Installation requires a 1-1/8″ crows foot wrench (not included) for the barrel nut; standard AR-15 barrel nut wrenches will not work with this handguard system. The handguard is secured to the barrel nut by 2 10/32 allen screws, stainless steel key seat lock, and anti-slip helicoils.