Purenex 4C-4GAC-4S-2I 5-Stage Reverse Osmosis Replacement Filter Kit with 14 Cartridges 4 of Granular Activated Carbon filters 5 Micron 4 of Block Activated Carbon filters 5 Micron 4 of Melt-blown Polypropylene Sediment filters 5 Micron 2 of Inline Pre/Post Membrane filters