The Evolution® Safety Helmet Cooling Sweatband is powered by HyperKewl™ PLUS evaporative cooling material. A unique fabric that absorbs and slowly releases water through evaporation, thereby protecting the wearer against heat stress for up to 10 hours ● this cooling sweatband is compatible with all Evolution® Revolution® Flex safety helmets ● product cools in 2 minutes ● machine washable at 60°C.