Sawyer SP121 Just Drink Inline Water Filter Biological Filtration: Sawyer Water Filters offer the highest level of biological filtration Removal rates: (7 Log Bacteria 99.99999-percent, 6 Log Protozoa & Cysts 99.9999-percent) 1 Million Gallons Guaranteed 0.1 Micron absolute hollow fiber membrane inline filter Use with a pump to prefilter, on a faucet adapter or inline in a hydration pack