Potable Aqua® Water Purification Tablets lead the way when it comes to making small quantities of even the most bacteriologically questionable water suitable to drink. Potable Aqua purifies water by wiping out bacteria and other micro-organisms such as viruses and protozoa. Used by the U.S. Military to purify water from outdoor sources in order to prevent water-borne health problems, Potable Aqua has been one of the most preferred methods of water purification among outdoor enthusiasts for years. This 50 tablet bottle will purify 25 to 50 quarts of water depending on the water source. Made in USA.