Stainless Steel Axle-Back Exhaust System with Split Rear Exit (40-2686) by JBA. Exhaust System Type: Axle-Back. Exhaust Tubing Material: Stainless Steel. Main Tubing Diameter: 3". Exhaust System Sound: Aggressive / Loud. For those who seek to transform their ride into a real beast, JBA offers this high performance product, built with durable design and efficiency in mind.