Mission Enduracool Lockdown Cooling Headband 80% Polyester, 20% Nylon Cools to 30 degrees below average body temperatures when soaked with water, wrung out and snapped Wicks away sweat from the head and promotes moisture cirulation Chemical-free; regulates evaporation to help cool UPF 50 sun protection Typically, stays cool for up to 2 hours when wet; to reactivate, simply re-soak and re-snap