The Peterbilt Ultracab XL Big Window 6 Inch Conversion Kit is a practical and versatile solution for enhancing your Peterbilt Ultracab XL. This kit includes a 6-inch cab extender and a pre-assembled fiberglass panel with a big window, providing a precision fit. The black, gray, or tan thermoformed plastic back wall, along with the OEM upholstery, adds a touch of elegance. With a pre-installed sound deadening core and a class 8 gel coat finish, this kit ensures a comfortable and stylish driving experience. The CNC cut and drilled panel, along with the included hardware and sealer, make installation hassle-free. Compatible with most Peterbilt Ultracab XL models, this kit is a must-have for truck enthusiasts.