UPF 50+ Sun protection/ Dermatologist recommended, and at the same time, wearing this hat, is like wearing an ice-cold towel. Soak our Chiller hats in cold water then wear them during your golf round. Chillers remain very cold for 5+ minutes, quite cold for 15+ minutes and comfortably cool until dry (1 - 3 hours). Re-chill with a quick refreshing splash as necessary. Adding water stops sweat and stains, It’s made of quality, synthetic suede that’s comfortable lightweight and rugged. It will not fade. The unique perforated fabric allows ventilation, but, blocks the sun. It may even improve your golf game! Hat Size Chart: Head Size Medium 6 1/2 to 7 (21" - 22 ") Large 7 to 7 1/2 (22 " - 23 1/2 ") X-Large 7 1/2 - 7 3/4 (23 1/2 " - 24") . Color tone may vary.