1.External USB charging port with charging cable is convenient to charge smart phone/tablet/other devices. Better for cleaning backpack, wont get usb rotted, replacing the cable by removing the built-in cable.
2. MULTIPLE COMPARTMENTS; Total 6 Compartments to save your belongs well. Backpack strap is well-padded and adjustable to fit your body. Comfort on your back. Backpack with built in USB CHARGER Port outside and built in charging cable inside,this usb backpack offers you a more convenient way to charge your phone while walking/work. Please noted that backpack doesn't power itself, usb charging port only offers an easy access to charge.
3. WITH Free Waterproof Rain Cover: External fabric is rip-resistant nylon that protecting backpack from scratch, dirt, sand and internal fabric is waterproof coating that keep from water, rain, fog