This is a handmade item that I made myself using a home sewing machine. It uses a 20cm zipper, and the outer fabric is Liberty's Tana Lawn with quilt batting attached, giving it a soft and light finish. The roses, branches, and birds make it a lovely piece. The sixth photo shows the contents I actually put in a pen case of the same size (not included with the product). Please use it as a reference. I think a ruler up to 18cm would fit (the ruler in the photo fit). Besides a pen case, I think it can be used in various ways. Size (outer dimensions) Width: Approximately 22cm Height: Approximately 7cm Depth: Approximately 5cm Please allow for some margin of error. I make each item with care, but there may be some imperfections. I would appreciate your understanding and acceptance of handmade items. Thank you for your purchase. Thank you for your consideration. ◆When making a purchase◆ Please also take a look at my profile. ※Liberty Strawberry Tree