Ergodyne Chill-Its 6675 Class 2 Evaporative Cooling Vest - Large/X-Large Class 2 Evaporative Cooling Vest: Soak in cold water. Enjoy cooling relief and enhanced visibility. Activated, polymer-embedded fabric inside 3M Scotchlite Reflective Material, 2" Level 2 ANSI-compliant Hook and loop closure and outside pocket Soak in water for 2-5 minutes to activate; remains hydrated up to 4 hours