Samson Manufacturing Corp. E2 Evolution 7" Rail Md: E2-EVO-7 E2 The Samson Evolution Series features a free-floating AR-15 rail system. Being lightweight and durable allows the Samson Evolution Series to offer the perfect upgrade for 3-Gun competition shooting, law enforcement and military personnel or weekend enthusiasts. 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. Rail accommodates most piston systems. Standard Evolution Series Includes: Thermal bushings, Two (2) 2" accessory rail kits, One (1) 4" accessory rail kit and wrenches. - Free-float - 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 - 1913 Picatinny Mil-spec - Precision laser engraving - Forms continuous top rail - Made in New Hampshire USA - Material: 6061-T6 aluminum - Finish: MIL-A-8625 type III class 2 anodizing - Model: EVO 7 - Length (in): 7" - Gas system: Carbine - Weight 7.9 oz - ID (in): 1.56 OD (in) 1.80