Multi-Functional Expandable Backpack with Vacuum StorageVacuum Compression: Features a one way valve for quick compression using an electric pump or manual pressing, optimizing luggage space. Odor, Dry, and Wet Isolation: Airtight vacuum bag with compartments for separating wet and dry items, keeping your belongings organized and protected. Expandable Capacity: Expands up to 40L, equivalent to a 24 inch rolling suitcase, and fits a 17 inch laptop. High Quality Material: Made of high density Oxford fabric