Product information : Capacity: 20-35L Internal structure of the bag: zipper pocket, mobile phone pocket, certificate pocket, computer insert pocket. Opening method: zipper Material: Oxford cloth Functions: waterproof, wear-resistant, anti-theft, USB charging, earthquake resistance, burden reduction and cutting prevention. Color: black, dark gray, disassembly wheel black. Size Information: Size: 34x22x48cm Packing list: Backpack *1