Aerostar 16 1/2x21 1/2x1 MERV 11, Pleated Air Filter, 16 1/2x21 1/2x1, Box of 6, Made in the USA

Nominal: 16 1/2 x 21 1/2 x 1, Size: 16 1/2"x21 1/2"x3/4" 16 1/2x21 1/2x1, 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.