Accumulair Diamond 25x32x1 (24.5x31.5) MERV 13 Air Filter/Furnace Filters (6 pack) Nominal size 25 x 32 x 1, actual size measures 24.5 x 31.5 x 0.75 Great for helping reduce airborne allergens such as bacteria, particles that carry viruses, pollen, mold spores, fine dust, and pet dander Each filter lasts up to 3 months Electrostatically charged filter media captures airborne allergens smaller than 1 micron Merv 13 rating