For Hunter HEPAtech Air Purifiers.Hunter models 30200, 30201, 30205, 30250, 30253, 30255, 30256, 30350, 30374, 30375, 30377, 30380, 30390, 37255, and 37375. Permanently "charged" HEPAtech® filter captures particles as small as 0.1 microns in size. Captures allergy causing smoke, pollen, dust, mold spores, pet dander, and other irritating allergens. Lasts up to 6 months under continuous use. 99.97% Effective Air Cleaning (99.97% effective at removing particles as small as 0.1 microns that pass through the filter*).From the Hunter Fan people...quietly improving your indoor air since 1886TM.*Based on the AHAM/ANSI AC-1 Test. Results may vary based on user"s environment and intended room of use.