The all-new Accumulairreg; Titanium is the highest efficiency Accumulairreg; filter on the market! The electrostatically-charged fibers capture microscopic allergens smaller than 1 micron! The unique mini-pleat design helps trap maximum amount of airborne pollutants. Antimicrobial protection discourages the development of mold, mildew, bacteria or other microorganisms in normal use. No chemicals are added to Accumulairreg;! Can last up to 3 months! Filter measures 18.25x22x1 (Actual Size).