Used only once Expandable Zippers Capacity Water-resistant Material Shoe Compartment Expandable Carry-on Backpack for Women: Size before expansion is 18.5x12.2x8.66 inch/47x31x22cm; size after expansion is 18.5x12.2x11.8 inch/47x31x30cm. The Travel backpack airline approved that can be carried in flight, it saves you a fortune on checked fees and is perfect for traveling or on business trips under the seat on the plane, perfect for 5-7 days of daily travel. Note: Please check with your airline for size restrictions before your trip. Roomy Capacity Travel Backpack: Two main pockets for personal items, clothes, and more; keep your items organized and easier to find. a laptop compartment for a 17-inch laptop. This Hiking Backpack is also designed with a waterproof wet bag and a separate shoe compartment, the wet bag is made of high-density waterproof material to help you separate wet and dry items, and the separate shoe compartment can help you better carry your shoes. Breathable Shoulder Straps & Anti-theft Multifunctional Design: This Outdoor Sports bag features soft, breathable foam padding and a sternum strap design for long trips. It easily adjusts and securely holds the backpack in place, reducing stress on the shoulders and back and keeping you cool during long backpacking sessions. The backpack with trolley cover slips over the trolley for easy carrying. There is a hidden anti-theft pocket on the back to protect your valuables from theft.