The Aero Precision Mil-Spec AR-15 Carbine Buffer Kit comes with everything you need to mount a stock on your rifle. The buffer tube is machined from 7075-T6 aluminum and features a durable Melonite finish. This Carbine receiver extension features 6 positions of adjustment for your favorite collapsible stock allowing you to customize to your length of pull. It features Mil-Spec dimensions for a tight, rattle-free fitment with most carbine stocks. Includes the heavier H2 buffer weight to reduce felt recoil on overgassed, suppressed, or short barreled rifles. Features: