This product requires a portable power bank to be configured for use, which we do not provide. Thank you 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 Comes with built-in functions, one click compression function, no need to purchase a pump yourself 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 The vacuum bag zipper is very easy to open and requires two hands to assist in opening. There is also an instruction manual inside, which is not a quality issue, but designed to prevent air leakage. Please be aware, thank you