Product Name: Vacuum Compression Backpack Material: Waterproof Oxford cloth Size: 49*32*15CM After expansion: 49*32*20CM Capacity: can hold a 17.3-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 boarding Large capacity = 24-inch luggage Quick Exhaust, The One-Way Air Valve Cabin Designed Based On The Principle Of Pneumatics Can Be Easily Pressed To Exhaust Without The Need For An Air Pump, Quickly Completing The Compression Process. 1. Open The Compressed Vacuum Lined Bag 2. Pack The Clothes And Zip Up The Airtight Zippers 3. Open The One-Way Exhaust Valve 4. Press To Expel The Air Inside