The Only EPA Registered Purification Tablets on the Market - effective against Cryptosporidium, Giardia, bacteria, and viruses. The only disinfection system effective against viruses, bacteria, cryptosporidium, and Giardia. Fresh tasting water - no unpleasant taste. Easy to use tablets. The same proven technology that is used in municipal water supplies. Lightweight and compact - ideal for traveling, lightweight backpacking, and emergency use.