This unique cooling vest uses a combination of evaporative cooling material with our specially designed Military Phase Change Cooling Inserts for maximum cooling time. With thousands of units in operational use, it is a proven tool of the US Military. Comfortable, quilted cotton-nylon outer w/polymer embedded fabric inner, and water-repellant nylon liner (excluding inserts). Phase Change Cooling Inserts maintain a comfortable 58°F (15°C). Include one (1) set of Phase Change Cooling Military Inserts (7065). 7.5 lbs.