The PackRight Sport 1 Car Top Carrier is constructed of 600D Hydrotuff, which is a UV-resistant, waterproof, polyester material. It features a waterproof ZipRight zipper that unzips 3/4 of the way around the bag to provide a large opening for easy packing. It also comes with come with a StrapRight four-pack nylon strap set that holds the carrier to two- or four-bar luggage racks. Even if you don’t have a luggage rack, you can still use the strap set to attach the carrier to most vehicles. For additional protection, consider the PackRight Waterproof Liner or the Non-Skid Roof Protection Pad, which will help hold the carrier in place.