This lightweight backpack folds into its own pouch. It is perfect "just in case" backpack for shopping, day trips, or once you reach your destination as an extra bag to carry home your new treasures. Lightweight material is water and dirt resistant. Opens to a full-size backpack, also has18 cubic liter roomy main compartment has 2 interior pockets, front compartment has media pocket and audio port and 2 water bottle pockets