The filter housing connects between 2 kegs, and non-carbonated beer is forced (with CO2) from the first keg, through the filter, and into the second ‘bright’ keg. The system includes 2 filter cartridges; a 5.0 micron filter which removes particulates such as hop debris, proteins and trub material that would clog the fine 1.0 micron filter. So easy to use; simply connect the 2 ball locks, and turn on the gas - the beer will flow and you will know that you’re beer is clear.