I received this as a gift, but I'm selling it because I don't have a chance to use it. It's lightweight and breathable, making it convenient for everyday use and running. It's new and unused, and the size is 27cm. I hope someone will find it useful. *Please note that this item is stored at home, so the outer box may have scratches, dents, or slight tears. Thank you for your understanding. The item will be shipped in simple packaging, so please purchase only if you are comfortable with this.