aFe MACHForce XP 2.5in SS-409 Cat-Back Exhaust 07-16 Jeep Wrangler (JK) V6-3.6L/3.8L (2-4 Door)The Hi Tuck "Rock Basher" Cat Back Exhaust System is constructed of 2 1 2" mandrel bent stainless steel tubing. The smooth curves and increased diameter of this exhaust system helps remove restriction and keeps exhaust gas flowing smoothly for increased horsepower, torque and throttle response. This exhaust system also comes complete with a 14" length high flow straight through designed muffler to absorb high pitch tones producing a powerful sound.