Chill-Its® 6685 Dry Evaporative Cooling Vests, X-Large, High Visibility Lime-YellowProvides immediate and long lasting cooling Up to 3 days of cooling ability each time the vest is filled Easy to use watertight filling cap Fill with 13 20 oz. (400 600 ml) of water to activate Lightweight, durable and washable V neck with zip closure Mesh side panels provide additional ventilation and stretch Patented Do not clean the inside reservoir; cooling material is treated with an anti microbial that inhibits mold growth Keep cap closed at all