- Material: oxford cloth 2. Capacity: 20 liters or less 3. Function: breathable, waterproof, wear-resistant, anti-theft, anti-vibration, lightening 4. Lining texture: polyester 5. Types of accessories: USB interface 6. Reflective design at night, beautiful and fashionable 7. The USB model comes with USB interface cable (not including power bank) 8. Double zipper design, smooth and durable 9. The junction of the shoulder strap and schoolbag is strong and not easy to break 10. Nylon material for hand-held, stronger bearing capacity 11. Dimensions: 30x14x45 cm 12. Weight: about 460 grams 13. With pen case and anti-theft lock, the USB model also includes a USB cable