Tier1 Replacement for 18x18x1 Merv 8 Pleated Dust & Pollen AC Furnace Air Filter 6 Pack Similar to the 3M Filtrete Dust & Pollen 18x18x1 Air Filter. Made in the U.S.A. Actual Size: 17 3/4 Inches (Length) x 17 3/4 Inches (Width) x 3/4 Inches (Thickness) NOVA Pleat, pleated fabric filter media. 3 Month Filter Life