18x20x1 MERV 13 (MPR 2200) Pleated AC Furnace Air Filters. Box of 6 18x20x1 MERV 13 (MPR 2200) Pleated AC Furnace Air Filters. Box of 6 Meets LEED Green Building criteria for minimum efficiency Actual Size: 17-3/8 x 19-1/2 x 3/4. Filter Rating: MERV 13 | FPR 10 | MPR 2200 Protects from pollen, dirt, dust, pet dander and virus carriers, smoke, smog, lead dust, oil smoke and micro allergens. Made in the USA