This is a binder for the popular Traveler's Company passport-sized notebook. The outer dimensions are approximately 4 cm thick, and it can hold 5 notebooks. I purchased it at the Kyoto store and kept it at home. (I just wanted to look at it, haha.) As of August 2025, it's sold on Amazon for 880 yen. It's almost unused and doesn't have any noticeable stains or scratches, but it's not new. The item will be packaged with cushioning material and shipped in an opened state.