this is a once size fits all hat. unfortunately, it doesn't fit unless you have a very, very large head. i wear 7.25 sized caps frequently and comfortably. this was probably closer to an 8 and made me look like i was a kid wearing adult clothing. i like the look and feel. it has a cloth exterior and fleece interior with extra lining around the brow and ear line, and it seemed that the hat was warm and well made, but it's just too big. i would have sent it back, but gave it to my dad instead, since he has a giant sized dome.