Both the outer and inner fabric are made from sustainable polyester, which is produced from recycled PET bottles. The impregnated material keeps the backpack waterproof. The soft rubber in the straps, back panel, and bottom provides comfort while protecting the contents without adding bulk. The straps can be easily adjusted in length without any loose ends hanging down. Due to its size and flexibility, the backpack is ideal for the city, university, or office. With its appropriate dimensions, the backpack easily stays within the usual carry-on limits for air travel.