Hi, Pleated air filters are the best choice, because these are more effective than electrostatic filters. Generally, Pleated filters have an average efficiency of 25-30. Pleated furnace filters include cotton, synthetic and polyester material for filtration. Some pleated filters contain charcoal or carbon to help eliminate odors in addition to filtering dust and impurities. 1 Inch pleated filters effectively remove pollen, dust, pet dander and dust mites for circulated indoor air. Thanks!!!!!!!