Hydropure 1 MICRON PS-PF 20" Sediment Filter is a unique polymer spun-wound cartridge filter that removes water contaminants that are 1 micron or larger in size. Unlike media filters, the 1 MICRON acts as a physical barrier, trapping a large variety of contaminants in its many layers. This includes rust, sand, allergens, human hair, and other harmful pollutants. Each layer provides a different degree of filtration, this design allows you to get the most out of your filter. It prevents premature clogging.