This filtration pack is extremely easy and powerful. All you have to do is drop the pack in any fresh water source. Produces approximately 12 fl oz of clean water. The Hydropack produces a safe, hydrating drink using Forward Osmosis. It also provides the highest level of filtration of any personal water treatment system because it uses a system of filter holes each only 5 ten-billionths of a meter! With a filter that fine, protozoa, bacteria and viruses don’t stand a chance.The clog-free filter wall allows for full hydration of 12-16 ounces in 8-12 hours completely hands free. NOTE- not for use in seawater or antifreeze.