MICROPUR MP1 Water Purification Tablets are for emergency disinfection of drinking water. When used as directed, the tablets release Chlorine Dioxide which is effective against Cryptosporidium, Giardia, bacteria, and viruses. 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. Purification Method: Chlorine Dioxide Tablets. Output: 1 tablet treats 1 quart (1 liter) of water. Capacity: Packets of 20 and 30 tablets. EPA Registered. Available in 20 & 30 pack.