Tacfire PK556-LPK-10 pistol kit. Everything you need to build out your 5.56 pistol just add a lower receiver.Includes: 10.5" Barrel Low profile gas block Pistol length gas tube A2 flash hider Bolt carrier group M-Lok hand guard Lower parts kit Upper parts kit Pistol buffer tube Buffer and spring Black Anodized DOES NOT INCLUDE A LOWER RECEIVER