Looking for an upgraded exhaust system for your Duramax? Check out the MBRP S6032BLK 4 Inch Black Series Filter Back Exhaust. This high-quality exhaust system is made from T304 stainless steel and features a 4" construction for maximum durability. It also includes a 5" OD exhaust tip for a more aggressive look and sound. Plus, the filter-back design ensures optimal airflow and performance.