The Geissele Premium AR15 Buffer Tube (08-162B) is machined from quality 7075-T6 Aluminum and finished in Type 3 Hardcoat Anodize. The 6 position carbine length and mil-spec diameter Premium Buffer Tube is made in the USA and weighs in at 3.7oz. Included in the package are a high-quality, mil-spec castle nut and endplate.