【Expandable Airplane Backpack for Carry-on Luggage】: Size: 51cm x 34cm x 17.5cm. Expanded size: 51cm x 34cm x 23cm. Weight: 1.9kg. Meets the carry-on requirements of many airlines, including EasyJet, Ryanair, Wizz Air, Lufthansa, and more. Note: Before traveling, check with your airline for exact size restrictions and fees. 【180° Opening】: The main compartment of the travel backpack can open 180° like a suitcase, allowing you to quickly pass through airport security. It is also convenient to quickly and easily organize your personal belongings such as clothes, towels, books, files, etc. Built-in elastic straps prevent clothes and items from getting lost and falling, making your trip more comfortable. 【Large Capacity & Multiple Pockets】: The large backpack's capacity is 30-40 liters. The bag has a total of 13 pockets: two front pockets for everyday items. Large compartments include wet/dry dividers and visible zippered mesh pockets. Hidden mesh pocket for water bottle/umbrella on the side. Separate padded laptop compartment for up to 17 \" laptop. Anti-theft pocket on the back. Keep your luggage organized. 【3 Ways to Carry & 3 Individual Pockets】: Use it as a travel backpack, flight-certified backpack, or tote bag. With two handles on the top and side of the cabin bag, it can be carried vertically or horizontally. The luggage straps on the back allow you to attach your cabin bag to your suitcase, freeing your hands and shoulders. 3 organizing pockets: separate shoe pocket, mesh pocket for clothes, laundry pocket. 【Comfortable Backpack】 The business backpack is made of breathable mesh and comfortable shoulder straps, and the buckles on both sides help you stabilize the center of gravity, reduce the burden on your shoulders, and make your trip very comfortable. Meets all the needs of business travelers, commuters, and outdoor enthusiasts. It is also the best companion for weekends, travel, fitness.