Breathable material: outer material of 17 inch laptop backpack men business 20L school backpack is oxford fabric and inside with polyester, the use of waterproof fabrics, water does not penetrate, water drops fall automatically, rainy days are not afraid of wetness. shoulder back with honeycomb, breathable, sweat, decompression. User-friendly design: Great design with external USB port and headphone jack travel backpack business rucksack men, convenient for charging your electronic devices and you can listen to your favorite music hands-free with a headphone jack on the go. Premium quality zipper to ensure efficiency.Breathable 8.5cm wide Two " S " Curve padded shoulder straps design, can effectively relieve shoulder pressure, so you can carry comfortably, long-distance travel won't be tired. Large capacity and multiple compartments: 20 x11.8 x 5.5 inch, large capacity and multiple compartments, 3 main pockets & 9 small inside pockets & 2 SIDE side pockets for 9 inch tablet PC and even 15.6 inch laptop, pen, keys, wallet, books , Clothes, bottle and more, keep your things organized and you never worry about your things getting crammed indoors. Suitable occasions: multifunction laptop backpack 15.6 inch black for every occasion, perfect for business trips, weekend trips, going to college, shopping and other outdoor activities in daily life. Great gift: The business backpack laptop bag waterproof computer daypack for men school / sports USB is a great item as business gifts. It is also suitable for travel and shopping. Ideal for serving as a bookbag, backpack, school bag and casual daypack for school, work, weekend trips, occasional trips, fitness studios, hiking, etc. Color: Black Material: nylonPackage: 1x backpack, NOT including other items, such as power bankNote: There is no mobile power supply with the backpack inside. If you want to use the external USB charging function, you need to do the following: 1. Connect your mobile power supply to the USB interface in the backpack. 2. Connect your phone to the USB interface outside of the backpack. 3. The loading process begins.