Aerostar 16x20x1 MERV 6, Fiberglass Air Filter, 16x20x1, Box of 6, Made in the USA Nominal: 16 x 20 x 1, Size: 15 1/2"x19 1/2"x3/4" 16x20x1, AC Furnace Air Filter Comparable to 3M Filtrete MPR 300 Dust Reduction Fights lint, dust, and pollen. Change frequency 30 days, Made in the USA.