The Hurricane is constructed with 100% radio frequency-welded seams and corners (eliminating needle hole leaks), a deeply recessed zipper that runs the perimeter of the unit, and heavy-duty vinyl, creating a truly weather-tough roof pouch. A wedge-shape aerodynamic design and two sets of straps for use on a vehicle with or without a roof rack complete this piece. The Hurricane comes with everything you need to use on a vehicle with or without a roof rack