Fellowes HF-300 True HEPA Filter, for use with Fellowes AP-300PH Air Purifier (9370101) True HEPA Filter captures 99.97% of particles and impurities as small as 0.3 microns Captures mold spores, pollen, dust mites, most airborne microbes, allergens and cigarette smoke Compatible with Fellowes AP-300PH Air Purifier This items packaging will indicate what is inside and cannot be hidden To ensure optimal performance, only genuine Fellowes filters shipped and sold by Amazon.com should be used. Filters purchased from third party sellers may not be authentic and therefore can cause issues and void product warranties