Made from approximately 1.5mm thick black oil leather. The entire perimeter is hand-stitched with black thread. Because thick leather is used, it has a sturdy construction. The size when open is approximately 20 cm x 30 cm. It can be used for notebooks and books up to about 2 cm thick. Images 1, 2, 3, and 4 show it attached to a book that is 1.7 cm thick. As shown in images 5 and 6, there are pockets on the left and right inside for cards and business cards, a pocket on the left for memo paper, a pocket on the right for a ruler, and a bookmark in the center. Since it is vegetable-tanned leather, the more you use it, the more depth of flavor it will gain, and you can enjoy the aging process. Please also enjoy the feel of the vegetable-tanned leather. The book, cards, memo paper, and ruler in the images are not included in the product. Because natural materials are used, there may be color unevenness, scratches, and wrinkles. Thank you for your understanding of handmade items.