The Daniel Defense Rail Interface System (RIS II) has provided to US Special Operation Command (SOCOM) since 2006. This revolutionary two-piece handguard attaches to the receiver with ourpatented, 6-bolt Bolt-Up System and free floats the barrel. Available in your choice of Flat Dark Earth or Black. FeaturesFree-Floating Barrel Design for Increased AccuracyTwo-Piece Design for USSOCOM Allows for the Attachment of an M203 Grenade Launcher When Lower Rail Section is RemovedBattle-Proven, 6-Bolt Bolt-Up System Securely Attaches Handguard to the Upper ReceiverGrade 8 Military Specification FastenersUninterrupted Upper Rail Platform & Mil-Spec 1913 Picatinny RailsMil-Spec Type III Hard Coat Anodized Finish (FDE or Black)The Daniel Defense RIS II M4A1 FSP feature a cutout in the toprail to accommodate a standard front sight base on a carbine length gas system