The Advanced Technology AR-15 commercial buffer tube assembly package fits most AR-15 and AR variants. It features a 6-position, 7.8" hard-coat anodized 6061-T6 aluminum buffer tube with a slanted back and commercial thread and tube diameters of 1.17". This assembly also comes with an AR-15 recoil plug, buffer spring and a steel castle nut and locking ring. Made in the USA. NOTE: This model is compatible with AR-10 308 models.