US Home Filter SC40-20X25X1-6 20x25x1 Merv 8 Pleated Air Filter (6-Pack), 20" x 25" x 1" Actual size: 19-1/2 inch x 24-1/2 inch x 3/4 inch Merv 8 tested under ashrae 52.2-2007 standards Ideal for normal air filtration and those with mild allergies Moisture resistant, heavy-duty Frame Galvanized expanded metal backing