The Honeywell AirGenius 3 Air Purifier's patented QuietClean ifD® advanced filtration system provides exceptional air cleaning performance. This portable air purifier comes with 2 pre-filters and a permanent washable foam pre-filter. You can also use the optimal odor reducing pre-filter (requires replacing every 3 months). The pre-filter helps capture larger particles before they enter the ifD® filter. The permanent washable ifD® primary filter helps capture up to 99.9% of microscopic allergens1, making this an excellent air purifier for allergies. The Honeywell AirGenius 3 features convenient LED controls, with 3 cleaning levels. Silent operation also makes this a quiet air purifier. K Genuine Pre-Filter This home air purifier works with the Honeywell K Pre-Filter. The Pre-Filter is the first level of filtration and helps capture large particles such as dust, lint, fibers and pet fur and helps to reduce VOCs & odors from cooking, smoke, bathrooms and pets. This filter. should be replaced every 3 months. The filter check/reset light will remind you when it’s time to change your filter. Initial filter included. To ensure stated product performance, use only genuine and certified Honeywell replacement filters.