Adding a tonneau cover to your big diesel truck is pretty much a must-have if you're going to keep cargo or gear in your truck's bed. Our friends over at Extang manufacture a variety of high-quality tonneau covers that not only clean up your diesel's looks, but can also add a nice layer of security to your truck's bed to protect it against the elements any prying eyes. Extang has a variety of Duramax tonneau covers, Cummins tonneau covers, and Powerstroke tonneau covers available in different styles, designs, price points, and functionalities so that you can find the perfect Extang tonneau cover for your application or your budget.