Product information: Color: 3201 commuter black, 3201 expansion black, 3201 upgrade black Material: Oxford cloth Capacity: 20-35L Function: waterproof Computer size: 16 inches Backpack system: air cushion strap Size Information: Specification: Commuter: (10cmx30cmx43cm) 13L Capacity expansion: (10~16cmx30cmx43cm) 21L. Upgrade: (19~25cmx30cmx45cm) 34L Packing list: Backpack *1