5" Downpipe Back exhaust for the 2001-2010 Duramax Trucks. It will replace the restrictive exhaust system with a 5" straight pipe high-flow system with no muffler and is designed for race applications. Comes with all the required clamps, pre-weld contour bent hangers, and stronger flanges to help you sail through the installation process. This exhaust not only sounds great but will help improve your mileage, torque, and throttle response in your Duramax!  T409 stainless