The AR-STONER Mil-Spec Buffer Tube is perfect for upgrading an existing or building a new AR-15. This buffer tube is machined to strict military standards to provide an excellent fit and reliable function. The AR-STONER buffer tube is machined from 6061-T6 aluminum and given a hard coat anodized finish to withstand years of abuse. Features6-Position AdjustabilityRugged Anodized FinishMil-spec Diameter, Carbine length