Replacement Filter Compatible with LEVOIT Vital 100 Air Purifier，part number Vital 100-RF，2 Pack 3-in-1 Filters Set：WASHABLE PRE-FILTER+ HIGH-EFFICIENCY ACTIVATED CARBON FILTER + TRUE HEPA FILTER 3-Stage Air Clean：WASHABLE PRE-FILTER（traps larger air contaminants like pet hair, dust balls）+ HIGH-EFFICIENCY ACTIVATED CARBON FILTER （absorbs household odors from pets, cooking, smoking and harmful VOC's）+ TRUE HEPA FILTER （captures 99. 97% of pollutants as small as 0. 3 μm such as dust, pet dander, and pollen） Replace the filter every 6 months.If your environment has high air pollutants,the filter change indicator may turn red within 6 months If you are not satisfied with anything, just contact us directly, we offer a prompt, courteous refund or a new replacement pack.