This Fits RAINSOFT ULTREFINER UF50 UF50T UF50N 50 GPD FILTER PACK – CITY WATER( Does Not Fit ULTREFINER II ) INCLUDES: ONE (1) RAINSOFT TFC-RS9-50 REVERSE OSMOSIS MEMBRANE 50 GPDONE (1) 10 MICRON CARBON BLOCK PRE FILTERONE (1) 10 MICRON CARBON BLOCK POST FILTER CHANGE THESE FILTERS EVERY 6-12 MONTHS.SANITIZE YOUR RO EVERY 6-12 MONTHS.ALWAYS LUBE THE MEMBRANE BRINE SEAL BEFORE INSTALLING TO AVOID DAMAGE.ALL ITEMS ARE NEW, NSF CERTIFIED AND FACTORY SEALED. Brand New Item Sealed in BagTHESE ARE THE PROPER FILTERS IF YOU HAVE CITY WATERReplace Membrane Every 6 months – 1 Year.Replace All Other Filters at Least Every Six (6) MonthsRAINSOFT COMPATIBLE FILTERSNot compatible with Ultrefiner II Don’t pay more for less! We ship sooner, faster, and for less than our competitors. We ship immediately. We charge you less than our competitors charge you for slower service. We combine shipping upon request. We will match all verified competitor’s prices. We ship internationally. Service makes the difference! MADE IN THE USA PRODUCT DETAILS: Rainsoft Membrane Part Number: 12448 (UF22T-CB & UF22N-CB)Rainsoft Carbon Block Pre Filter Part Number: 18557 (UF22T-CB & UF22N-CB) and 18773, 9757, 12464, 13119, 17368Rainsoft Carbon Block Post Filter Part Number: 18557 (UF22T-CB & UF22N-CB) and 18773, 9757, 12464, 13119, 17368Rainsoft Ultrefiner Compatible membrane for the Ultrefiner, UF22, UF22T-CB, UF22N-CB, UF20, 9564, 9568, 9596, 9596N, 9798 (without post filter), M-T1810R24, 12446, 13018, 17374, 21176, 21191 reverse osmosis systems. NSF/ANSI Standard 58 Tested and Certified This membrane removes or reduces the following contaminants: arsenic, barium, chromium, cadmium, copper, cysts, fluoride, lead, radium, selenium, turbidity, TDS, nitrate, nitrite, magnesium, calcium, sodium, nickel, mercury, zinc, iron, ammonium, bicarbonate, sulfate, tannin, chloride, bromide, and sediment. For best results, this membrane should be changed every 1-2 years based on water quality and usage. Pre and Post Filters should be changed at least every 6 months to extend the life of your RO Membrane.