Increase horsepower and torque with a deeper, more aggressive exhaust note. Welded from mild steel, then bathed in a four-step chrome-plating process. Tri-Flo muffler begins as a 4″ muffler at the front and morphs into a 4″ x 5-3/4″ oval at the rear. All necessary mounting hardware and instruction included, ensuring problem-free installation. Made in the U.S.A..