FeaturesMaterial: nylon; Capacity: 36-55L Large travel backpack. Casual backpack is light to carry, breathable, adjustable shoulder straps, comfortable to carry, can reduce the pressure on the shoulders when traveling. You can put it in your luggage when you travel. Smooth double zippers make it more convenient and easier to access your belongings. And it's sturdy, strong and won't fade. USB port design. There is a USB charging port extension on the side of the backpack with a built-in charging cable, so you can easily charge your phone when you are out and about with your backpack (POWER BANK not included).Opening pocket: Zipper Waterproof, anti-theft, wear-resistant, shock-resistant expansion and reduction design: (1) back zipper back pocket on the back of the backpack can protect your valuables, such as cell phones, passports, wallets, etc. from being stolen while traveling or standing in line; (2) waterproof polyester material, which can protect your water-invasive items. (3) Ergonomic airflow design on the back, thick and soft multi-panel breathable padding for added support and comfort. Multifunctional Backpack. This backpack can be carried around, or to work and school, can be easily stored, casual style, suitable for daily travel, commuting, business travel, outdoor activities , shopping, school