The legendary performance of Tilley hats continues with the Hikers Hat. Of course it will completely shield you from both sun and rain, but it also pairs an evaporative insert with mesh venting to help you keep your cool during those warm weather treks. Simply soak the insert in water and place it in its secret mesh pocket. Cools as evaporation commences. Re-activate as necessary. You can even freeze it for extreme heat use.3/4? AIRFLO? mesh to assist evaporative properties of cooling insert.Certified UPF 50+. Guaranteed for Life.