Aerostar 20x25x1 MERV 11 Pleated Air Filter, Made in the USA, 6-Pack Nominal Size: 20 x 25 x 1, Actual Size: 19 1/2" x 24 1/2" x 3/4" Comparable to 3M Filtrate 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