NSF Tested and Certified: Our filters are tested and certified by NSF international against NSF/ANSI Standard 42. Premium Carbon Block: The carbon block used in our refrigerator cartridge is made of pure coconut shell carbon in a “block” construction, the structural design of which offers a high contaminant-absorption rate. Excellent Filtration Performance: The advanced filtration technology ensures that these replacement water filter cartridges reduce chlorine, odor and taste. Providing you with clean and healthy water! Satisfactory Capacity: Enjoy better drinking water for up to 300 gallons or 1,137 liters each filter. Replace your filter every 6 months for optimum performance. Compatibility: Replacement for Fisher & Paykel 836848, 836860, PS2067635, 67003662, RO185014, RO185011, WF60, C2; Model number: ActiveSmart, E402B, E402BRXFDU, E402BRXFDU4, E404BRXFDU, E442B, E442BRXFDU4, E522B, E522BLXFDU4, E522BRXFDU, E522BRXU, E522BLXFDU, E552B, RF201A -- PLEASE NOTE: The Waterdrop 836848 is NOT compatible with refrigerators using model codes beginning with RS90A, RS9120 and RS36, nor part-numbers 847200 and 842802.