The Geissele Premium Mil-Spec Buffer Tube is machined from quality 7075-T6 Aluminum and finished in Type 3 Hardcoat Anodize. This rigid and durable buffer tube conforms to all mil-spec standards and features 6 stock positions. This carbine length and mil-spec diameter Premium Buffer Tube is made in the USA and weighs in at 3.7oz, making it the perfect fit for your AR-15 lower and ensuring compatibility with most mil-spec diameter quality AR-15 stocks. Included in the package is a high-quality, mil-spec castle nut and end plate.