Samson EVO7EX Evolution 7" AR-10 7" 6061-T6 Aluminum 7" Evolution Series 7-EX The Samson Evolution Series is the next step forward in free floating hand guards. Light weight and durable these offer the perfect upgrade for 3 gun shooters LE/Military or weekend enthusiasts alike. Accessory picatinny rails can be added or removed at any of 7 positions around the rail and any place along the length of the tube. Kit includes: Thermal bushings (2) 2 " rail kits (1) 4 " rail kit instructions & wrenches.Rail Accommodates most piston systems. Carbine Length Free Float Design Thermal bushings clip to any mil-spec barrel nut Relieved for Most Gas Piston Systems No Need To Remove Front Sight Base Rail Includes Integrated Anti-Rotation Tabs All Rails 1913 Picatinny Mil-Spec Type III Mil-Spec Hard Coat Anodizing Precision Laser Engraving Forms Continuous Top Rail 6061 T6 Aluminum Overall Length: 10.0 " Weight: 9.2 oz ID: 1.56 " OD: 1.8 "