Filtering out dust, pollen, mould spores, cigarette smoke and a whole range of other undesirable airborne particles, Fellowes HEPA AeraMax Filters are perfect for ensuring quality air.Stopping 99.7% of all particles and catching impurities as small as 0.3 microns, you have a more reliable way of preventing disease. Perfect for people that are suffering from respiratory diseases such as asthma and bronchitis.