While bacteria has the greatest potential to cause sickness, viruses can be lethal promoting the creation of the Virus Ultratfiltration Hollow Fiber Membrane. This enhanced filter removes virus that can affect you while camping, traveling, or in any emergency situation for 10,000 gallons. Hollow Fiber works through size exclusion. Dozens of hollow tubes have microscopic holes (0.02 microns) and act as a barrier to viruses such as Hepatitis A, Polio, Typhoid, and Enteroviruses. Additionally, in a similar way it blocks 99.999% of bacteria. Clean water is allowed to passthrough the holes while the large contaminants cannot fit through the holes. To clean the hollow fiber, simply rinse clean water through the opposite direction of the flow of water. This will push contamination and debris back out the inlet and will extend the life of the filter.