Build a Complete 20 Fluted Bull Barrel AR Kit. This kit contains everything you need to build your own AR except the stripped lower receiver. - The Kit Contains: - Fully assembled 20 Fluted Bull Barrel Upper with 15 Keymod Palm Handguard - Your choice of either an MBA-1 Buttstock Assembly or MBA-3 Buttstock Assembly - Complete Lower Parts Kit - Add to your build with optional add-on parts such as a Velocity Drop-in trigger or The Lower Enhanc-AR Kit. - This Kit does not come with the lower receiver. You will have to supply a lower receiver purchased elsewhere. We recommend that you look for a Mil-Spec stripped lower. - Includes: - Your choice: MBA-1 Fixed Rifle Buttstock assembly or MBA-3 Adjustable Carbine Buttstock Assembly - LLRPK-1 Complete .223/5.56 Lower Receiver Parts Kit - Assembled Complete 20 Fluted Bull Barrel Upper: - HG-V-15K Palm Handguard Vented 15 KeyMod with Barrel Nut - BL-B18FT 20 Bull Barrel Fluted Threaded 416 SST - FTT-EA1 A3 Upper Receiver Assembled - BC-A-223 Fully Assembled Bolt Carrier .223 - BL-04 Rifle Length Gas Tube - GB-LP936 Gas Block .936 - BL-06-A2 A2 Flash Hider - Barrel Specs: - 20 Fluted Bull Barrel - .223 Rem - 416 SS - Threaded Barrel Thread Pitch 1/2 x 28 - Gas Block Diameter .936 - Gas Tube Length 16 Carbine 18 20 and 24 are Rifle - 1-9 RH Barrel Twist - 6 Lands and Groves - M4 Feed Ramp - Button Broached