2-Pack Replacement Holmes HM2409 Humidifier Filter - Compatible Holmes HWF62 Air Purifier Filter Replacement Holmes HM2409 Humidifier Filter Replaces Holmes HWF62 Air Purifier Filter. Quantity: 2 Slows down the growth of bacteria, mold and mildew For best results, change air filter at least once per season or more often depending on air quality and use. Essential for Allergy Sufferers. On Sale for a Limited Time!