COOLING COMFORT TECHNOLOGY - Stay active longer even when the temperature rises with a cooling and invigorating MISSION Cooling Helmet Liner. Sweat it or Wet it, this skull cap keeps you cool and fits great under helmets and hard hats. | COOLS INSTANTLY - When activated with water MISSION performance fabric cools up to 30 degrees below average body temperature in under 1 minute! Activate quickly in 3 easy steps: Wet it, Wring it out, and Wave it. This hat stays cool for up to 2 hours! | LIGHTWEIGHT VENTILATED HEADGEAR - Feather-light fabric is fitted to keep sweat out of your eyes and not slip off or interfere with helmets. Ventilated Mesh construction at the crown promotes airflow for maximum breathability and moisture wicking. | SO MANY USES! - Ideal for wearing under bike and motorcycle helmets, a football or baseball helmet, or wear alone for exercise like running, soccer, and cross training. This skullcap works and plays as hard as you do! | CHEMICAL-FREE COOLING & UPF 50 Sun Protection- The cap is reusable and machine washable, with permanent chemical-free HydroActive Cooling Technology that will never wash out. It also provides UPF 50 sun protection.