The AR-STONER(TM) Extreme Duty Receiver Extension Buffer Tube is perfect for upgrading an existing AR-15 A2 Stock or building a new fixed stock AR-15 rifle. This buffer tube is machined to strict standards to provide an excellent fit and reliable function. The AR-Stoner buffer tube is machined from 7075 aluminum and given a hard coat anodized finish to withstand years of abuse. Includes buffer tube only. Buffer and buffer spring sold separately. FeaturesHigh Grade Impact Extruded 7075-T6 Aluminum Construction Buffer TubeRugged Anodized FinishFits AR-15 A2 Stocks