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 12 Months 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 12 Months 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. We offer two replacement filter kits so you can get exactly what you need — and avoid paying for filters you don’t. Year 1 Kit found on this page (Includes RO Membrane):Ideal for your first full replacement, this kit includes all filters plus the RO membrane, which typically lasts up to 24 months. Year 2 Kit (Without RO Membrane):After the first year, you only need to replace the pre- and post-filters, since the RO membrane is still good for another year. This kit helps you save money while keeping your system performing like new. *Filters may need to be replaced more often than indicated, depending on water contaminant levels and volume of water being treated.