Tilley Airflow Hat : Let the Airflo®! The Tilley Airflo® provides sun protection in a lighterweight construction. Tilley Airflo® designs incorporate mesh into the crown allowing coolness and comfort during hot days or strenuous activities. Engineered from Tilley Nylamtium®, a strong water-and-mildew resistant form of nylon. Brim Measurements: Front and Back: 3 1/2" Sides: 2 1/2" Made in Canada