Filtrete Micro Partical Reduction Filter, 800 MPR, 14-Inch by 20-Inch by 1-Inch, 6-Pack Microparticle Performance Rating of 800 Captures large airborne allergens like household dust, pollen,lint, dust mite debris, and mold spores Keeps furnace or air conditioner running efficiently Outperforms comparable fiberglass and washable/reusable filters Pack of six filters