US Home Filter SC60-24X24X4 24x24x4 Merv 11 Pleated Air Filter (3-Pack), 24" x 24" x 4" Actual size: 23-3/8 inch x 23-3/8 inch x 3-5/8 inch Merv 11 tested under ashrae 52.2-2007 standards Ideal for those with moderate allergies Moisture resistant, heavy-duty Frame Galvanized expanded metal backing