HYDROSOLVE Outdoor Portable Water Filter Camping Emergency Water Purification System with Hand Pump Filtration for Hiking and Camping (Portable Water Filter)The second stage of the filter system is a sediment filter with a 5 micron filter pore size that filters sand, mud, rust, coarse sediments and turbidity. The third stage of the filter system is an ultrafiltration membrane that is proven to filter out 99. 9% of all microorganisms from the water. The ultrafiltration works similar to a coffee filter, only that the filter is ultra fine. The water to be filtered is pressed with pressure through small