Filtrete Micro Partical Reduction Filter, 800 MPR, 16-Inch by 20-Inch by 1-Inch, 2-Pack Outperforms non-electrostatic filters, comparable fiberglass and washable/reusable filters Microparticle Performance Rating of 800 Pack of two filters Captures large airborne allergens like household dust, pollen,lint, dust mite debris, and mold spores Keeps furnace or air conditioner running efficiently