Raw aluminum. 04-17 thick style. Used to mount exhaust to cylinder head. Note: Exhaust retaining rings are required for installation. These must be ordered separately. Note: The thinner 84-03/17-22 'Early Style' steel and the thicker 04-17 'Late Style' aluminum exhaust flanges are interchangeable. Late Style flanges are thicker and designed to help prevent bending of the exhaust flange. All will fit all 84-up Big Twin and 86-up XL Sportster models.
