UpStart Battery Replacement Hunter 30200 Air Purifier Filter - Compatible Hunter 30930 Air Filter Replacement Hunter 30200 Humidifier Filter Replaces Hunter 30930 Air Filter 3 Filtration Layers for the best air purification: 1st layer removes large particles from the air, 2nd layer removes particles as small as .1 microns, 3rd layer removes odors such as tobacco smoke, cooking and musty air 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!