Sun Hat shading, decoration, warming and protective functions. So many choices there.
First according to face shapes to choose the right hat. People faces the main square (face), circular (round face) and sharp (sharp face) three.
Round face with a domed CAP, it is face, small hats. Such as wearing a large cap is appropriate. Tip it face to face who wears a cap on small, even more gaunt. Dai Yuan CAP is appropriate. Face who wears all the hats are appropriate.