The Geissele premium mil-spec buffer tube is crafted from high-quality 7075-T6 aluminum and finished with a type 3 hardcoat Anodize for exceptional strength and durability. Conforming to all mil-spec standards, this buffer tube features six stock positions and is carbine length with a mil-spec diameter. Weighing just 3.7oz, it fits perfectly with your AR-15 lower and is compatible with most mil-spec AR-15 stocks. Made in the USA, the package includes a premium mil-spec castle nut and end plate. Paired with the Geissele Super 42 spring, designed for enhanced function and reliability, this spring uses three independent strands of wire, similar to the German MG42 Machine Gun. This unique design acts as a harmonic damper, improving energy absorption and reducing spring failure while eliminating annoying spring "twang." The Super 42 spring also offers a 15% stronger average return force, aiding in reliable cycling, even with dirty rifles or steel-case ammo. Constructed from high-quality 7075-T6 aluminum Completed with type III hardcoat anodize finish Number of stock positions is 6 The innovative spring design incorporates three separate wire strands The super 42 spring exhibits an average return force that is 15% stronger than that of the standard buffer spring