The AR-STONER(TM) 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(TM) buffer tube is machined from 6061 aluminum and given a hard coat anodized finish to withstand years of abuse. Note: Includes buffer tube only. Buffer and buffer spring sold separately. FeaturesMachined from Durable AluminumRugged Anodized FinishFits AR-15 A2 Stocks