The FreshWater 'Garnet' carbon block replacement water filter cartridge is for installation in the second and third housings of the FreshWater MRO30K Revese Osmosis (RO) water filter unit. Their role in the RO set up is to remove chlorine to protect the RO membrane and to condition the water prior to it entering the storage tank.
The 'Garnet' cartridge will also fit most industry standard RO units with the industry standard 'Open Both Ends' cartridge mount configuration. If you are unsure which cartridge you need please don't hesitate to contact us.