Nominal: 20 x 20 x 1, Size: 19 3/4"x19 3/4"x3/4" 20x20x1, AC Furnace Air Filter Comparable to 3M Filtrete MPR 1000 to 1200 Micro Allergen Defense Comparable to Honeywell Allergen Plus FPR 7 Fights lint, dust mites, mold spores, pollen, pet dander, dust, and smoke. Change frequency 60-90 days, Made .
