Advertised (Nominal) Size: 24 x 24 x 1, Size: 23 1/2"x23 1/2"x3/4" 24x24x1, AC Furnace Air Filter, (Pack of 4 Filters), MERV 13, comparable with MPR 1500-1900 Comparable to 3M Filtrete MPR 1500 to 1900 Ultimate Allergen Defense, and Honeywell Allergen Elite FPR 10 BREATHE CLEANER: Fights bacteria and virus carriers, lint, dust mites, mold spores, pollen, pet dander, dust, smog, and smoke: Creating a fresh and healthy home.