This BCA AR-15 complete 5.56 Nato rifle length upper has a 16" M4 contour barrel with a parkerized finish, and features a 1:8 twist rate, with a carbine length gas system. It includes a 15" MLOK rail, an M4 flat-top billet upper receiver, a BCA bolt carrier group, a flash hider, and a left side charging (Gen 2) handle (patent protected) left ejecting. This 5.56 Nato upper is compatible with any mil-spec AR-15 lower.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