This backpack has a simple yet stylish design. The charging module can be folded and hidden for use in different business or personal situations. You can charge the portable power bank during the day using the external solar panels. When using the outside USB connection for electricity, the internal USB will be cut off automatically, and vice versa. Double-layer multi-inner bag design make the partition clear and more orderly. Small items are safely stored in the front section and larger items are placed in the rear section. In order to reduce fatigue, the shoulder strap is wide and thick with air permeable sponge.