Chrome Tri Flow MufflersIncrease 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..