Timber Creek Outdoors ULE15HGBL Ultralight Enforcer 15" Aluminum for AR-15
https://www.tandktactical.com/shop/816397024518-timber-creek-outdoors-ule15hgbl-ultralight-enforcer-15-aluminum-for-ar-15-47801
https://www.tandktactical.com/web/image/product.template/47801/image_1920?unique=fe5a057
Requires low profile gas block, Two mil-spec 1913 picatinny rail sections