Accumulair Titanium High Efficiency Allergen Reduction Air Filter/Furnace Filters (2 pack) Nominal size is 24x30x1. Actual size is 23.5 x 29.5. The all new Accumulair Titanium is the highest efficiency Accumulair filter on the market! Electrostatically charged fibers capture microscopic allergens smaller than 1 micron! Unique mini-pleat design helps trap maximum amount of airborne pollutants Contains odor-reduction technology!