This Bear Creek Arsenal AR-15 Complete 5.56 rifle length upper has a 20" heavy barrel with a black nitride finish, and features a 1:7 twist, with a rifle 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 side charging (gen 2) handle (patent pending). This 5.56 upper is compatible with any mil-spec AR-15 lower. This has the new handguard.Shop more 5.56 NATO Uppers!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