Product Name: Vacuum Compression Backpack Material: Waterproof Oxford cloth Size: 49*32*15CM After expansion: 49*32*20CM Capacity: can hold a 17-inch laptop Separate laptop bag Using the vacuum compression method: 1. Open the compressed vacuum lined bag 2, put the clothes on the air-tight zipper 3. Open the one-way exhaust valve 4. Press to exhaust the air inside Function: Breathable back Comfortable foam shoulder straps strap Anti-theft zipper pocket on the back Waterproof/wear-resistant/moistureproof Wet and dry separation area vacuum compression airtight Password lock boarding Large capacity = 24-inch luggage