Et Arms Inc Buffer Tube Kit Carbon Fiber Black, Mil-Spec For AR-15, Ambi Sling Endplate Included This Amazing Super Light-Weight Mil-Spec Buffer Tube Is engineered using Carbon-Fiber Reinforced Composite Material, More Resilient To Damage Than Aluminum. This Tube With Castle Nut & ambi End Plate sets Standard For The Next Generation Of AR Shooting Enthusiast! Type: Buffer Tube Material: Carbon Fiber