Blocks 80% of solar heat and harmful UV rays and has an evaporative cooling liner that is activated with water. Ideal for camping, hiking, gardening, tourism, fishing, boating, hunting and any outdoor activities used in other seasons Durable, breathable and lightweight construction The evaporative cooling inner liner retains cool water and slowly evaporates to keep your head up 20°F cooler. Simply wet the inner lining and put on the hat! Get instant relief from the heat and stay cool for hours Nylon cloth + knitted fabric + EVA foam.The fabric that makes up every Hydro Cooling Bucket Hat is lightweight and breathable.