Our revolutionary evaporative cooling hat uses a patented Hydroweave system that actually uses the sun's energy to cause evaporation that draws heat away from your head. You charge the hat by running it under cool water; after its excess water is wrung out, the hat keeps your head up to 30° cooler than the outside air temperature while keeping you dry and comfortable. The Hydroweave system combines hydrophilic (water-attracting) and hydrophobic (water-rejecting) fibers in a three-layer fabric that conducts body heat upwards, while retaining the cool water and releasing it slowly through evaporation; even while the middle layer holds onto water, your head remains cool and dry thanks to an inner lining that water can't permeate. The en d result is a hat that actually cools you more effectively the hotter the air temperature. Cotton and polyfiber blend. One size fits most; adjustable hook-and-loop back. Imported. Available in Navy or Khaki. 4 1/2" H x 7" W x 10" D. (2 oz.)