This USB backpack makes it easier than ever to charge your phone. Please note that this backpack doesn't power itself; the USB charging port only offers easy access to charge your devices. It has secret pocket on the back will always keep your important items safe. Convenient removable keychain gives easy access to key storage and usage. Easy to use with removeable clip. It is designed with comfortable airflow foam pad back with thick but soft multi-panel ventilated breathable mesh padding gives you maximum back support. Both sides of the shoulder strap with lanyard design. It is suitable for daily use, school, office, camping, hiking, travel, good breathability, good heat dissipation, two padded shoulder straps, light to carry, forcibly reinforced to reduce shoulder pressure, keep cool when carried for a long time.