The Katadyn Micropur tablets are EPA registered effective against Cryptosporidium, Giardia, bacteria, and viruses. They are designed to offer fresh tasting water with no unpleasant taste and utilize the same proven technology as municipal water supplies. Features: 20 pack. Disinfection system effective against viruses, bacteria, cryptosporidium, and Giardia. Fresh tasting water with no unpleasant taste. Easy-to-use tablets. Same proven technology that is used in municipal water supplies. Lightweight and compact. Purification Method: Chlorine Dioxide Tablets. Output: 1 tablet treats 1 quart (1 liter) of water.