EXCEPT eTorque Mild Hybrid System and Full-Time 4 Wheel Drive. The 2.5 in. diameter Borla High Clearance Climber / Rock Crawler Cat-Back system for the Wrangler JL is designed with ground clearance in mind. This system is perfect for off-roading, overlanding, and rock crawling. It features the classic S-Type Sound with no drone inside the vehicle. The exhaust exits thru a 2.5 in. brushed T-304 stainless steel turn down tip. Each system is built from premium T-304 stainless steel giving you the absolute best in performance and durability and is a direct bolt on designed specifically for the 3.6L engine. Ultra-smooth mandrel bends ensure maximum flow & power, and precision Computer Numerical Control (CNC) manufacturing ensures an accurate fit.