Mission Enduracool Techknit Cooling Towel, Large, Blue Fish 90% Polyester, 10% Nylon Cools Instantly When Wet to 30 Degree below average body temperature Premium Tech Knit material. Lightweight & Breathable Chemical-free, Reusable & Machine Washable. Lightweight, UPF 50 protection against the harmful rays of the sun When dry, the soft knit material absorbs sweat and wicks moisture away from the skin To activate cooling technology: Get it soaked, wring out excess and snap three times. Typically, the towel cools for up to 2 hours when wet. To reactivate, simply re-soak and re-snap.