Accumulair Titanium 20x27x1 (Actual Size) High Efficiency Allergen Reduction Air Filter/Furnace Filters (4 Pack) The all new Accumulair Titanium is the highest efficiency Accumulair filter on the market! MERV 13 Rating. Each filter lasts up to 3 months. Uniform pleat shape enhances dust holding capacity and maximizes air flow. Supercharged pleated panel filtering media ideally suited for capturing fine airborne allergens such as dust, smoke, dander, mold, pet dander, and dust mites. 4 Pack of Air Filters