Kaw Valley Precision 6 Position Mil-Spec Stock Completion Kit with SS Buffer for AR-15 builds. Kit includes a 7075-T6 aluminum Mil-Spec 6-Pos buffer tube with matte black anodized finish, a 17-4 stainless steel carbine buffer spring, and a heavy stainless steel buffer (4.3 oz). Also included are the carbine stock end plate and castle nut (stock hardware) to complete a Mil-Spec stock installation. This kit is designed to upgrade or convert to a Mil-Spec adjustable stock compatible with AR-15 platforms. Two models are available: 4.3 oz and 5.4 oz SS buffers. Weight of the kit is listed as approximately 0.5 lb.