Accumulair 20x20x5 (20.75x20.25x5.25) MERV 8 Aftermarket York Replacement Filter MERV rating: 8 Nominal Size: 20x20x5 Actual size: 20-3/4x20-1/4x5-1/4 Part number: DPFPC20X20X5=DYO Nominal Size 20 x 20 x 5. Actual Size 20.75 x 20.75 x 5.25 Great for reducing air borne particles such as dust, pollen, mold spores, tobacco smoke, pet dander and particles that carry viruses High efficiency filter media collects small dust particles before they can collect on your coils Merv 8 Efficiency Lasts up to 6 Months