The Frigidaire WF1CB PureSource Refrigerator water filter fits all Frigidaire Energy Star compliant refrigerators manufactured in 2001 with a round filter housing (not a slide out filter). The filter cartridge itself has blue ends. It replaces Frigidaire part numbers RF100, RG-100, RG100, and Sears Kenmore part number 46-9910, used in Kenmore refrigerators that are made by Frigidaire (model numbers starting with 253). It improves the taste and odor of the water and removes the following impurities: 98.30% of Particulates (Class III), and 96.50% of Chlorine (Class I). It Does Not Remove Flouride. Frigidaire recommends that you replace the filter every 9 months or when the filter status light turns red, whichever comes first OR if the refrigerator has not been used for more than two weeks (for instance, during a move) OR if you notice a decrease in the flow of water or objectionable tastes in the water or ice.