Expandable backpack

Capacity: 20-35L Internal structure of the bag: ID bag, mobile phone bag, sandwich zipper bag, zipper pocket, computer slot Opening method: zipper Applicable gender: neutral / male and female Material: Oxford spinning polyester Function: waterproof, breathable, wear-resistant, anti-theft, lightening, shock resistance Processing method: embossing Hardness: medium to soft pattern: plain Style: Fashion Sports Outdoor Leisure Lining texture: polyester Strap root number: double root Lifting parts: soft handle Bag shapes: square vertical section Carrying system: curved shoulder strap Color: grey, black