21x22x1 (Actual Size) Accumulair Emerald 1-Inch Filter (MERV 6) (6 Pack);

Up to 30-times more efficient at capturing allergens than ordinary fiberglass filters. Uniform pleat shape enhances dust holding capacity and maximizes air flow. Heavy duty construction frame prevents airflow bypass. This product is listed and rated by Underwriters Laboratories as U.L. Class 2.