Product Name: Expandable Backpack Accommodates a 17-inch laptop Material: High-density Oxford cloth Weight: 1KG Shoulder strap: Adjustable length: 24-66CM Capacity: 40L Function: USB charging interface, breathable design, three-dimensional honeycomb back pad, high elasticity, breathability, shock resistance, Shoulder strap clip. Back fixed, can be used with trolley case, waterproof material