Reduces up to 95% of airborne particles catching pollutants such as Smog, pollen, smoke, pet dander, mold spores, and fine dust as small as 1 micron. MERV 13 at a minimum is 50% efficient at capturing particles with diameters between 0.3 microns and 1 micron and provides a superior level of filtration and protection from particles that cause asthma and other air quality related afflictions. Many types of bacteria and large sized viruses are also captured at this level of filtration efficiency, improving indoor air quality and protecting your health. Most brands of filter lose efficiency over time as they trap airborne pollutants and particles, with this line of filters you’re guaranteed MERV 11 protection during the life cycle of this filter in your HVAC system!