This kit contains everything you need to build your own AR except the stripped lower receiver. The Kit Contains: Fully assembled 16" .223 Rem Fluted Bull Barrel Upper with 15" Keymod Palm Handguard(R), MBA-3 Adjustable Carbine Buttstock Assembly, Complete Lower Parts Kit. This Kit does not come with the lower receiver. You will have to supply a lower receiver purchased elsewhere. A Milspec lower is recommended.