Aerostar 14x20x1 MERV 8 Pleated Air Filter, Made in the USA, 6-Pack Nominal size: 14 x 20 x 1, actual size: 13 1/2" x 19 1/2" x 3/4" Comparable to 3M filtrate mpr 600 clean living Comparable to Honeywell micro defense plus fpr 5 Fights lint, dust mites, mold spores, pollen, pet dander, and dust Change frequency 60-90 days, made in the usa