Simpliwater UF filter cartridges are designed as "Dead-End" filters, removing removing at least 99.99% all particulates, including but not limited to Bacteria, cysts, viruses, mold and algae. Filtration is rated at 0.02 microns as specified by the manufacturer of the "Ahlstrom" media, a patented one of a kind product. These cartridges fit standard American filter housings purchased online or at your local hardware or Box Stores.