Thule Paramount Commuter Backpack 28L 4 Day Highly ventilated Large ventilation Full length Light Weight Highly ventilated Large ventilation channels in the protector combine with ventilated fabrics for optimal heat management the backpack includes a channeled luggage handle pass through so you can easily stack with your suitcase Large side pocket Large side pocket holds a water bottle or insulated container securely while riding or walking water resistant finish free from PFCs (chemicals that can be harmful to the environment) and coated base material on the bottom of the bag all provide extra layers of durability and protection that stand up to everyday use