The Peterbilt 579 and 567 NGP Low Roof XL 4 Inch Conversion Kit is a practical solution for those looking to extend their cab. This kit includes a pre-assembled fiberglass panel with pre-installed bracing and sound deadening core, making installation a breeze. The CNC cut and drilled panel ensures a precision fit inside the flange, while the class A gel coat finish adds a sleek look. The kit includes all necessary hardware and sealer and fits most Peterbilt 579 and 567 NGP Low Roof XL models. Upgrade your cab with this 4 inch cab extender and enjoy the added space and comfort.