I bought this for my son, but he only wore it briefly once or twice. He doesn't wear hats much, and I have too many winter hats, so I'm selling this one. The size seems like it would fit an adult woman, so I estimate it's around 52-56cm. There's no tag, but I remember being told at the hat shop where I bought it that it uses Italian yarn. I'm not certain, so please be aware of that. Knit cap Green Pattern: Solid Color: Green