Daniel Defense M4A1 Rail Interface System II Black DD-8001-BLK. 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. The Daniel Defense RIS II is to be used in conjunction with the MK12 Low Profile Gas Block. Specifications for Daniel Defense M4A1 Rail Interface System RIS II: Manufacturer: Daniel Defense Gun Make: AR Platform Gun Model: M4A1 Gun Type: Rifle Handguard Length: 12.25 in Gun Rail: Picatinny Weight: 17.7 oz Condition: New Included Accessories: Standard Height: 2.25 in Quantity: 1 Width: 2.23 in Length: 12.25 in Features of: 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-Tested 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 or Black) Inside Diameter 1.15" Barrel Nut - Steel (For Patented Bolt-Up System) Package Contents: Daniel Defense M4A1 Rail Interface System RIS II Daniel Defense Warranty: Guaranteed Satisfaction All Daniel Defense products carry a 100percent satisfaction guarantee against defects in original materials and workmanship. If your Daniel Defense product shows evidence of such defects Daniel Defense will make every accommodation to fix repair or replace your product in the most expeditious manner possible. Daniel Defense does not warranty products or damage caused to our products by the correct or incorrect installation of other manufacturer's products. Warranty information and warranties are supplied solely by the manufacturer and not this retailer. This retailer publishes information from the manufacturer for information purposes only and the manufacturer is solely responsible and liable for any warranty information and warranties published by this retailer. Please reference the appropriate manufacturer documents or reach out to the manufacturer directly for full warranty terms and effective dates. Daniel Defense M4A1 Rail Interface System II Black