Tilley LTM8 Nylon with High All Mesh Crown Hat 100% Nylon Imported LTM8 Nylon with High All Mesh Crown Hat by Tilley Brim measures 3.5 inches front and back and sides measure 2.5 inches Weighs 4.8 ounces Floats in water For the proper fit, you should be able to easily insert two fingers, flat, between the middle of your forehead and the front of the hat.