Replacement Composite Prefilter for USWF RO-2F-600 tankless Reverse Osmosis SystemThe RO 2F 600 F is the replacement prefilter cartridge for the USWF tankless RO system. The composite prefilter combines polypropylene sediment filtration and an activated carbon block that lasts 12 months or 1000 gallons. The composite filter reduces chlorine, dirt, and other suspended particles to protect and extend the life of the system's RO membrane. Built in water shutoff means the filter change can be accomplished in just 3 seconds without the