Internal structure of the bag: zipper pocket, mobile phone pocket, document pocket, interlayer zipper pocket, computer pocket Function: breathable, waterproof, wear-resistant, anti-theft, USB charging, shock-resistant, capacity expansion, load reduction, anti-cut, dry and wet separation Lining texture: polyester Color: black small 48*18*30cm, black medium 53*21*32cm, black large 40*23*60cm Waterproof degree: water repellent Computer size: 17 inches