This true HEPA Filter captures 99.97% of airborne particles as small as 0.3 microns, including pollen, ragweed and other allergens, viruses, germs, dust mites, mould spores and cigarette smoke.Its AeraSafe antimicrobial treatment provides built-in protection from the growth of odour causing bacteria, mildew and fungi on the True HEPA filter.Compatible with Fellowes AeraMax 300 Air Purifier.With normal usage, it is recommended that you change your filter every 12 months to keep your air purifier running at peak performance.A filter change indicator on your Fellowes AeraMax 100 Air Purifier conveniently notifies you when it's time to replace your True HEPA filter.