MSR's® MiniWorks® EX Water Purification System delivers the viral protection you'll appreciate while backpacking wilderness areas or if you travel developing countries. This comprehensive system uses a ceramic and carbon element that filters out and is 99.99% effective against viruses, 99.9999% against protozoa and 99.9% against particulates. This ensures safe, taste-free water at one liter per minute. When viruses are a concern, add a chlorine-based iodine-free Aquatabs® tablet for extra certainty. Filter can be cleaned repeatedly. Compact, easy-to-use system meets United States EPA requirements for microbiological water purifiers. Wt: 1 lb.