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