DAN RIS II M4A1 FSP RAIL FDE The Daniel Defense Rail Interface System (RIS II) was designed at the request of the United States Special Operations Command (SOCOM) for the SOPMOD II program. SOCOM had a specific requirement for a free float M203 solution and Daniel Defense responded, designing a revolutionary product to meet the government’s need. The Daniel Defense RIS II allows the individual operator to free float the M203 grenade launcher without additional parts. As important, special tools are not required to mount the M203 grenade launcher. This was accomplished by integrating all of the needed parts to free float the M203 into the rail itself. KEY FEATURES • Aircraft Grade 6061-T6 Aluminum • Free-Floating Barrel Design For Increased Accuracy • Two-Piece Design for USSOCOM Allows For the Attachment of an M203 Grenade Launcher When Lower Rail Section is Removed. • Battle-Proven, 6-Bolt Bolt-Up System Securely Attaches Handguard to the Upper Receiver • Grade 8 Military Specification Fasteners • Uninterrupted Upper Rail Platform & Mil-Spec 1913 Picatinny Rails • Mil-Spec Type III Hard Coat Anodized Finish (FDE) Product Weight: 17.1 oz Rail Length: 12.25" Width: 2.23" Height: 2.25" Inside Diameter: 1.15" Barrel Nut: Steel (For Patented Bolt-Up System) Gas System: Carbine Free Float: Yes Continuous Upper Rail: Yes