A polyester, one-size-fits-all hat with a mouth guard to keep you warm. - Brand: TRANSCOOT - Material: 100% Polyester - Size: One Size Fits All (Width 12cm, Length 56cm) - Features: Polyester lining, includes mouth guard Thank you for looking. I tried it on once, but it was too small, so I'm selling it. (My head circumference is 57cm, for your reference.) It can be cinched slightly with the drawstring. It's fluffy and warm. It has been home laundered. I own a small dog. Please consider this before purchasing. The original price was ¥4,290, so this is a great deal!!