FEATURES: 1. Effective Against: Viruses (99.99%), bacteria (99.9999%), protozoa (99.9%) and particulate. Meets U.S. EPA drinking water standards* and NSF protocol P231 testing standard. 2. Iodine-Free: Aquatabs tablets inactivate viruses without bad-tasting iodine. Includes 50 individually packaged tablets. Each tablet treats up to 2 quarts of water depending on conditions. 3. Reliable: Filter’s durable ceramic/carbon element ensures safe, taste-free water—even with frequent, heavy use. 4. Field-maintainable: Filter can be cleaned repeatedly for full flow recovery with no tools required.