Stay cool and protected - The Polar Hat has amazing evaporative cooling technology, that keeps you cooler than the outside temperature. The built-in UV barrier reflects the sun's heat and harmful UV rays. Put it on for instant relief or wet the inner lining and get the ultimate cooling relief. You'll feel significantly cooler instantly and it will last for hours. The secret is the evaporative lining that holds and gradually releases water for continuous cooling. Perfect for the beach, the boat, going on a hike or any outdoor activity. It's fully adjustable so one size fits most. Made from Nylon and Knitted Fabric & EVA Foam