This hat is very warm with fur. 100% nylon, one size fits all. Used a few times, but has been cleaned. You can adjust the size slightly by moving the chin strap to the back (photo 5). If you fasten the chin strap under your chin, it won't blow away in the wind. Made of nylon, so it won't get wet even if it snows. I used this when I went skiing, but how about it for children's snow play or going to school? Measuring the tape on the inside with a measuring tape, it's about 57-58cm. This is just an amateur measurement. The stand used for taking the photos is not included.