Size: 17 3/8"x23 3/8"x1 3/4", nominal: 18 x 24 x 2 18x24x2, 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 in the usa.
