This vest has a 3 litre ice bladder built-in for easy to reload for continuous cooling over extended periods. The products use a combination of ice water and pumps to push cold water through special flat water compartments on the vest. This allows for a continuous flow of cool water around the body core keeping the user cool and comfortable in any condition. This is no evaporative phase change or air-cooled vest this is the best most affordable circulating water-cooled personal cooling vest. Commonly used by people with multiple sclerosis and other medical conditions and outdoor workers such as welders bee keepers coplayers hvac technicians solar installers recycle and steel mill workers. Any usb 2.0 Batteries will work flat water compartments give more skin surface contact for better heat exchange. Built-in water bladder on the back for easy to carry. Completely self-contained system with unlimited mobility. Built-in ice water circulating system delivers the right temperature to your body core. Powered by any usb batteries not included side velcro adjustment fits snugly around your body get the maximum cooling effect vest weight w o water: 28 oz. Plus 3 litre ice water weight. Cooling time: cooling time varies depending on the body size ambient temperature and how cold and how much ice to begin with. You only get exact the ice water gives you. No more and no less. However it s very easy to reload ice you can sit in a chair you can drive
