HVACQuick.com Accumulair 4 Inch Filters - MERV 11 FA21X22X4

21x22x4 (20.5 x 21.5 x 3.625 Actual Size). Accumulair MERV 11 Filters. Accumulair Platinum Series MERV 11 Filters - 4 inch thickness. Supercharged pleated panel filtering media ideally suited for capturing fine airborne allergens such as dust, smoke, dander, mold, pet dander, and dust mites - attracts particulates like dust to a TV screen. Uniform pleat shape enhances dust holding capacity and maximizes air flow. Up to 30-times more efficient at capturing allergens than ordinary fiberglass filters. Heavy duty construction frame prevents airflow bypass. Lasts UP TO 3 months. This product is listed and rated by Underwriters Laboratories as U.L. Class 2.