B511 - C509 Specifications: 5? Diameter Tubing T304 Stainless Steel Brush Finish, Polish Tip & Logo, 3.5? Diameter Dual Luster Laser Cut Tip Sound cancelling internal Helmholtz design to remove drone at cruising speeds Tucked high on the vehicle for optimal ground clearance Catback Bolt-on System Aggressive, deep throaty sound on acceleration This exhaust is designed to withstand the elements for true off-road use while adding an aggressive sound and quality look to the Wrangler JKU. Made from high end T304 Stainless Steel, the integrity of the exhaust?s material will not rust out like many of the low cost mild steel options on the market. The Helmholtz chamber built into the muffler attacks drone at cruising speeds, allowing for a comfortable highway ride without restricting the deeper exhaust notes on acceleration. Backed by Thermal?s lifetime manufacturing warranty, the Thermal JKU Exhaust is the perfect addition to the JKU owner?s build.