Check the listing for details. Rainsoft UF22 Compatible RO Filter Kit with Membrane. Condition: New. Listed at 97.97 USD. 1-Year Filter Replacement Kit with RO Membrane for RainSoft UF22 Reverse Osmosis System INCLUDES: * STAGE 1 - 1x Carbon Block Pre Filter (OMB934-5M) - Replace every 6-12 months or as needed * STAGE 2 - 1x RO Membrane TFC 22 GPD (TFC-RS9-22) - Replace every 24 months * STAGE 3 - 1x Carbon Block Post Filter (OMB934-5M) - Replace every 6-12 months or as needed Note: If your Rainsoft reverse osmosis system is from 2013 or newer, it most likely is the Ultrefiner II. The Ultrefiner II requires proprietary filters that must be purchased from a Rainsoft dealer. Conversion kits to generic non-OEM replacement filters are available. Filters may need to be replaced more often than indicated depending on incoming water contaminant levels and volume of water being treated.