Check the listing for details. iSpring RTW5 Compatible Filter Kit (Membrane Sold Separately). Condition: New. Listed at 53.96 USD. 1-Year Compatible Replacement Filter Kit for iSpring RTW5 Reverse Osmosis System (RO Membrane Sold Separately) INCLUDES: * STAGE 1 - 1x Sediment Pre-Filter (93023) - Replace every 6-12 months or as needed * STAGE 2 - 1x Carbon GAC Pre-Filter (OCB934RO T33) - Replace every 6-12 months or as needed * STAGE 3 - 1x Carbon Block Pre-Filter (OMB934-5m) - Replace every 6-12 months or as needed * STAGE 4 - 0x (RO Membrane 555694-00 Sold Separately or with Replacement Kit YSM-ISPG-RTW5) - Replace every 24 months * STAGE 5 - 1x Inline Carbon Post Filter 2" x 10" (K2533-JJ) - Replace every 6-12 months or as needed Filters may need to be replaced more often than indicated depending on water contaminant levels and volume of water being treated.