I guess most hats are "one size fits most" as this didn't seem to have a size listed. My head's a little bigger than average though not huge, and it was snug. Someone with a really big head will need to look elsewhere. It seems rugged and washes off well. I did have to struggle with the strap and the clasp on it sometimes, it seems like it could've been designed to slide easier or something. As far as sun protection I can't say much, except that wearing it and also some suntan lotion on my face and neck I didn't get burned.