Shop › BAD WRKHS 15" RAIL .750 GBLOCK COMBO BAD WRKHS 15" RAIL .750 GBLOCK COMBO $189.99 Battle Arms Development WORKHORSE 15" Rail and .750 Gas Block, Anodized Finish, Black, Fits AR-15 WH-UR-UPG Quantity: Add To Cart Added! Battle Arms Development WORKHORSE 15" Rail and .750 Gas Block, Anodized Finish, Black, Fits AR-15 WH-UR-UPG