Precision machined from 7075 aluminum, our mil-spec AR15 carbine buffer tube ensures proper fitment of adjustable mil-spec sliding stocks. This kit includes an H, Heavy Buffer and is designed to increase reliability in rifles, carbines or pistols with short gas systems. These parts would be perfect for your new build or as direct replacements for worn out parts. Heavy buffers are traditionally selected when you are trying to slow the down the movement of the BCG under recoil. Common situations to use a heavy buffer include over-gassed barrels, or when you are assembling an AR pistol or short-barreled configuration.