Use this exhaust system when you want to upgrade your Jeep Wrangler JK's sound and performance on and off - road. It's perfect for Jeep enthusiasts who love a deep exhaust note and want a durable, easy - to - install product. The main piping is 2.5 inches in diameter, and the tips are 4 inches. It fits various models of 2007 - 2018 Jeep Wrangler JK with 3.6L or 3.8L engines.