This is a book cover from the Marugoku series, purchased at the Correction Exhibition. I took it out of the OPP bag after purchasing it, but it has been stored unused at home for a long time. I searched for book sizes and found that: Bunkobon (pocketbooks) are 148mm tall x 105mm wide. Shinsho-ban (new books) are 182mm tall x 103mm wide. While it can be used for bunkobon, it will likely fit shinsho-ban books perfectly. I look forward to doing business with someone who understands that this is a used item.