USB charging computer backpack $ 81.39 Case size: medium Capacity: less than 20L Internal structure: ID bag, mobile phone bag, sandwich zipper bag, zipper pouch, computer insert bag, camera insert bag Open cover: Zipper Material: Nylon Model No. : 1.3. k3-DG 18L Processing: Frosting Series: backpack, handbag Bearing system: curved shoulder strap Color: Black and dark Size: 15.6 inches(473418cm)