This Bear Creek Arsenal AR-15 Complete 5.56 Upper has a 16 M4 barrel with a parkerized finish, and features a 1:8 twist, with a carbine length gas system. It includes a 15" MLOK rail, a M4 flat-top billet upper receiver, a BCA Bolt Carrier Group, Flash Hider, and a rear charging handle. This 5.56 upper is compatible with any mil-spec AR-15 lower. This has the new handguard. Visit our YouTube channel to see our AR-15s and AR-10s in action and get answers to common questions about your gun. Shop more 5.56 NATO Uppers!Bear Creek Arsenal manufactures all AR-15 rifles, complete upper assemblies, barrels, bolt carrier groups (bcg), and components in-house here in Sanford, NC. Choose an American-made AR-15 complete upper assembly from Bear Creek Arsenal, designed for high accuracy and backed by a lifetime warranty. Check out Magazines here!{{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="56"}}*Note - We strive to provide the most accurate photographs of our product. Variations may occur in the skeletonized section of the handguard/flash hider you receive.{{widget type="Magento\Cms\Block\Widget\Block" template="widget/static_block/default.phtml" block_id="42"}}It is the responsibility of the consumer to ensure all state, local, federal, and ITAR regulations are followed