3M Filter Ac Micro 18x30x1in MPR rating 1500 3 month filter is 90% effective at capturing large allergens like mold spores &amp; pet dander Electrostatically charged Attracts and captures dust, pollen, dust-mite debris, mold spores, pet dander, smoke, smog, bacteria, and more Improves air quality by cleaning air with each pass through the filter