It is given a MERV 8 filter rating, which means that it is a medium-efficiency filter that removes airborne particles smaller than 1 micron.
Accumulair FB21. Filter; Pack Of 4 Even with high particulate efficiency, it manages to maintain low resistance to airflow. This means that it removes a large variety of indoor air pollutants, including dust mites, bacteria, mold spores, pet dander, pollen, lint, and smoke. Also, composed of hydrophobic fibers, this filter does not support the growth of microbes like bacteria, mold, mildew, or fungi.