Filter Replacement Kit for Vertex PWC-7000 Reverse Osmosis System (RO Membrane Sold Separately) INCLUDES: * STAGE 1 - 1x Sediment Pre-Filter (K5605-JJ) - Replace every 6-12 months or as needed * STAGE 2 - 1x Carbon GAC Pre-Filter (K5633-JJ) - Replace every 6-12 months or as needed * STAGE 3 - 0x (RO Membrane 655045-00 Sold Separately or with Replacement Kit YSM-VERPWC7) - Replace every 24 months Filters may need to be replaced more often than indicated depending on water contaminant levels and volume of water being treated.