The Peterbilt Unibilt XL DIY 6 Inch Conversion Kit is a practical and convenient solution for extending the cab of your Peterbilt Unibilt XL truck. This kit includes a pre-assembled fiberglass panel with a window, as well as a pre-installed sound deadening core for a quieter ride. The CNC cut and drilled design ensures a precise fit to the factory rivet line, making installation a breeze. Sold as a kit, it is compatible with most Peterbilt Unibilt XL models. Upgrade your truck with this conversion kit and enjoy the benefits of a 6-inch cab extender.