Atomic 16x20x1 Merv 13 Allergy Elite Pleated Air Filter - 6 Pack Maximum Protection for Your Family's indoor air quality Electro Static Pleated for increased particle holding capacity and air flow Protects HVAC system and allows it to operate more efficiently saving money MERV 13 air filters efficiently efficiently filters allergens like dust, pollen, mold and pet dander Recommended replacement every 3 months