Product manualOur school bag Made of durable polyester fabric and metal electroplated zipper, using exquisite tailor process to support a long service time for your daily using. Serve you well as professional business office work bag, business travel backpack, big book bag, college high school student backpack for boys, girls, teens, adults. This 17 inch business backpack is an ideal present for men women or back to school graduation presen.This USB backpack has an external USB charger and a built-in charging cable, which provides a more convenient way for you to charge your mobile phone while walking. Please note that this backpack cannot be powered by itself, the USB charging port can only be easily chargedIf you have any questions about our products, please contact us immediately, we will solve it for you within 24 hours!