Outdoor Research Sunbriolet Sun Hat

The Sunbriolet offers UPF 50+ protection with superior breathability. The mesh-lined crown and side vents keep your head cool, and the quick dry moisture wicking headband keeps the sweat out of your eyes. The varied brim is wider at the back to protect the neck from the sun, and a narrower brim keeps the face and eyes protected without blocking the view. 

To size, measure around your head where the hat would fit comfortably.

Medium: 55-57 cm 
Large: 57-59 cm 
XL: 59-61 cm