Filtrete 20x20x4 Air Filter, MPR 1550 MERV 12, Ultra Allergen Reduction, 1 Filter Add Sponsored $47.96current price $47.96Filtrete 20x20x4 Air Filter, MPR 1550 MERV 12, Ultra Allergen Reduction, 1 Filter 2374.6 out of 5 Stars. 237 reviews Filtrete 16x25x4 Air Filter, MPR...