The JE Machine Skeleton Machined Mil-Spec AR-15 Pistol Buffer Tube is an uncompromising look at the mission to create an ultra-lightweight AR Pistol Tube without surrendering an ounce of durability. Meticulously milled from 6061 Aluminum and Type II Anodized. Boasting 14 individual pass through cuts, and a solid full length fluted underchannel, it's no surprise that this tube is the go-to choice for people that measure their success by the gram. FeaturesMilled from 6061 AluminumType II Anodized14 Pass through cuts for maximum weight reductionLength is 7.19"; Inner Diameter: 1"; Outer diameter: 1.24"