Catalon is the basic material for cartridges to Geyser pitchers. It is the fibrous material developed and patented by the Geyser Company. It removes viruses, bacteria, and all known municipal water contaminants. The cartridges have the same mounting dimensions, they are mutually replaceable and can be mounted in any Geyser pitcher (they can be mounted with appropriate adapters in pitchers of other producers, e.g. Brita or Barier).