These 0.2 Micron Air Filters have a fine enough filter membrane that they can filter out microbes and bacteria.
They can be used with any oil free air compressor such as a pond pump, or other type of pump.
These can also be used as an airlock in the top of your fermenter. They can also be used to filter air going back into a cask when dispensing real ale.
This filter is not suitable for liquids and should be discarded if it gets wet.