This is a Patagonia backpack. I purchased it at Ishii Sports last year and used it once. There is no size indication, but it is estimated to be around 18 liters. It has a removable laptop case inside. I bought it, but it doesn't suit my needs, so I'm putting it up for sale. I think it's the perfect tool for business people and students who carry a laptop every day. I remember the purchase price was around 20,000 yen.