Dimensions: 17.7 (H) x 11.8 (L) x7 (W) inches (normal). 11.8 (L) x 17.7 (H) x 10.6 (W) inches (extended), suitable for 17.3 laptops. For the maximum allowed size of an IATA flight, design enough space for your personal belongings for a trip of 5 to 7 days. Large and Flexible CapacityCompressed capacity of 26L. The full-length zip creates 30% more packing space between 26 and 40 litres. A total of 16 pockets in this bag, including dry/wet dividers, ensure a clear storage of your luggage. Open the zipper and buckle on the side, and this backpack can be easily enlarged. Multi-carry backpack Use as a daypack, flight tested carry-on bag or handbag. With the side handle, the bag can be turned into a handbag when your shoulders are tired. The rear strap allows you to attach the backpack to the luggage handle and the concealed backpack straps. In the back pocket that is near your back, you can store your passport, ID cards, cash and other valuable things when travelling and travelling. WaterproofUSB PortSelection of high quality water-repellent, scratch-resistant, tear-resistant special nylon and breathable, abrasion-resistant microfiber faux leather. Little rain or water drops will not penetrate the bag.When you connect a mobile battery in the backpack via a USB port, you can charge your smartphone while you carry it.