Brownells AR-15 Rifle Receiver Extension & Buffer Kit Features The Brownells AR-15 Rifle Length Buffer Tube Kit is made from Mil-Spec 7075 aluminum and features a matte black hardcoat anodized finish giving builders a durable corrosion-resistant foundation for a rifle length stock system. The buffer tube measures 9 5/8 inches in length and 1.110 inches in diameter matching standard Mil-Spec dimensions for direct compatibility with common rifle length buttstocks. This kit includes a buffer and spring designed to fit standard AR-15 and M16 lower receivers giving builders everything needed to complete the stock assembly in one purchase. For builders who need genuine Mil-Spec fitment without mixing components from multiple sources the Brownells AR-15 Rifle Receiver Extension & Buffer Kit delivers that consistency in a single package. The recoil spring is built from 17-7ph stainless steel cold drawn to ASTM A313 T631 specification giving it the durability and consistent tension needed for reliable cycling over years of use. The buffer s 7075-T6 aluminum construction keeps weight consistent with Mil-Spec standards ensuring proper function with a wide range of rifle length stocks and springs. For builders completing a rifle length AR-15 or M16 lower this kit provides Mil-Spec hardware without the guesswork of sourcing individual components. For AR builders who want proven Mil-Spec reliability in their buffer system this kit delivers that dependability in one complete package. Brownells AR-15 Rifle Receiver Extension & Buffer Kit Specifications Manufacturer: Brownells Model: AR-15 Rifle Receiver Extension & Buffer Kit Type: Buffer Tube Kit Color: Black Finish: Matte Black Hardcoat Anodized Material: 7075-T6 Aluminum Compatible Hosts: AR-15 M16 Buffer Tube Type: Rifle Buttstock Fit: Rifle Length: 9.625 in Width: 1.110 in Available At: GrabAGun