The Aquapak converts sunlight into thermal energy sufficient to kill all known water-borne human pathogens. It can heat 3 liters (3 quarts) of water to 67 degrees Celsius (150 F) in less than three hours during a typical sunny day when placed perpendicular to the sun. Can be used on boats, vehicles, roofs, the ground, or even strapped to your back. The Aquapak is engineered with a unique cap that houses a perpetually reusable water pasteurization indicator. Uses: emergency preparedness, disaster relief, hiking, camping. Weighs 6 oz. when empty.