This is a tweed fabric casquette. It fits well because there's elastic in the back. I've worn it about 3 times and stored it in my closet. There's no size label, but I measured it with a tape measure and it's 54cm (please understand that there may be some error due to amateur measurement). *It will be folded small for shipping, so please be aware of wrinkles. *Please purchase only if you understand that this is a used item.