16" x 24" x 1", Green, Dust Reduction Filtrete Filter, 3 Month Filter, Electrostatically Charged Fibers Attract & Capture Large Airborne Allergens Like Pollen, Household Dust & Lint, Ideal For High Velocity Heating/Cooling Systems, Performs Better Than Ordinary Fiberglass & Washable 1" Filters, For Residential Use Only, MPR Rating 600, Lasts Up To 3 Months.