Electrolux PureOxygen Allergy 400 Multi-Pet Allergen & Odor HEPA 4-Stage Filtration Air Cleaner / Air Purifier, White Premium HEPA filtration absorbs 99.97% of dust and allergens from the air down to 0.3 microns in size High deodorization filter offers superior odor and gas reduction and is recommended for pet owners Change filter indicator will automatically let the user know when it is time to replace the filters Auto Mode sets the fan speed to automatically be adjusted by the air quality sensorthe more particulates sensed, the higher the fan speed Replacement filters for this model are EL049 HEPA and EL050 Carbon