This set includes all five filter stages that require annual replacement.* The set comprises:
1st Stage - 5 Micron Sediment Inline Filter
2nd Stage - Activated Carbon Inline Filter
3rd Stage - Activated Carbon Inline Filter
4th Stage - 50GDP TFC Membrane
5th Stage - Post Carbon Filter
The UV bulb is not included and must be bought seperately for those with the M-Series with UV.
* Cartridge longevity and performance depend on water usage and level of contamination.