Filter Replacement Kit with RO Membrane for Microline CTA-14D Reverse Osmosis System INCLUDES: * STAGE 1 - 1x Sediment Pre-Filter (S7011) - Replace every 6-12 months or as needed * STAGE 2 - 1x RO Membrane CTA 14 GPD (S1224RS) - Replace every 24 months * STAGE 3 - 1x Carbon GAC Post-Filter (S7025) - Replace every 6-12 months or as needed * STAGE 4 - 1x Inline Carbon GAC Post Filter (K2333-KK) - Replace every 6-12 months or as needed Filters may need to be replaced more often than indicated depending on incoming water contaminant levels and volume of water being treated.