Oceanweave 600D reclaimed fishnet polyester with waterproof polyurethane coating. Water-resistant stitched construction. Lightweight universal Velcro attachment system attaches to the top of rack. Padded/insulated construction controls internal temperature and keeps load quiet - perfect for transportation of snacks. Main compartment expands vertically for an additional 2.9L / 177 cu/in. Side pockets expand to provide an additional 5.8L / 254 cu/in. Top bungee system for additional flexible storage. Ultra-stiff polypropylene backing plates built into fold-down pockets. External rear zippered pocket. Internal mesh pocket in lid. Adjustable internal divider