Classic business commuting style. Level 4 waterproof repellency. 18L larger capacity. 15.6inch laptop holder. 3 layer comfortable carrying system. Sandwich-style back panel, cooling and breathable. With back strap, can be attached to pushrod of suitcase. Mesh material Polyester Capacity 18L Size 280 x 150 x 430mm / 11.02 x 5.91 x 16.93inch Color Black, Dark grey, Dark blue, Light blue Weight 550g Package included: 1 x Xiaomi 18L backpack 1 x Desiccant 1 x Tag.