Geissele premium mil-spec buffer tube and Super 42 spring elevate your AR-15's performance with the Geissele premium mil-spec buffer tube and Super 42 spring, engineered for excellence and reliability. The buffer tube is crafted from high-grade 7075-T6 aluminum, precision machined and finished with a type 3 hardcoat Anodize for unmatched durability and wear resistance. It conforms to all mil-spec standards and features six adjustable stock positions for versatility and a custom fit. Weighing only 3.7 oz, it ensures seamless compatibility with most mil-spec diameter AR-15 stocks. Proudly made in the USA, the package includes a robust mil-spec castle nut and end plate for secure installation. The Geissele Super 42 spring is a revolutionary enhancement designed to boost the function and reliability of your AR-15. Inspired by the German MG42 Machine Gun, its unique design incorporates three independent strands of wire, functioning as a harmonic damper and energy absorber. This innovative approach allows the springs to flex independently, dissipating excess energy and reducing the risk of spring failure. The result is a more reliable firearm, even under challenging conditions. Compared to standard buffer springs, the Super 42 spring maintains its length and force over extended use, offering a 15% stronger average return force. This increased force aids in stripping rounds from the Magazine, particularly beneficial in dirty environments or when using steel-case ammunition. Additionally, the Super 42 spring eliminates distracting spring reverberations (twang), enhancing the overall shooting experience. Upgrade your AR-15 with the Geissele premium mil-spec buffer tube and Super 42 spring for superior performance, reliability and comfort. 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