2-into-1 equal-length headers. 1-3/4″ to 1-7/8″ headpipes. Recommended for Sportsters 1200 on up. Utilizes an advanced inner collector for maximum performance. Stainless steel Construction with Hand Tig Welding. Stainless Megaphone muffler. Made in the U.S.A.. For use with Mid-Controls. Includes 18 mm O2 sensor ports and 12 mm adapter.