iSpring F3 Water Filters, White iSpring high capacity 6-month replacement filter pack for 5-stage reverse osmosis systems, tested by independent third-party to meet NSF/ANSI Standard Fits iSpring 5-stage, 6-stage & 7-stage RO systems. Also compatible with all industry standard sized 10-inch filter housings 1st stage - 5 micron high-capacity polypropylene sediment filter removes dust, silt, rust and other particles from the source water 2nd stage - 5 micron granular activated carbon filter gets rid of unpleasant chlorine, tastes and odors 3rd stage - 5 micron carbon block filter removes any residual chlorine, volatile organic chemicals (VOCs) and other harmful chemicals