HVACQuick.com Accumulair 4 Inch Filters - MERV 8 FB21X22X4

21x22x4 (20.5 x 21.5 x 3.625 Actual Size). Accumulair MERV 8 Filters. Accumulair Gold Series MERV 8 Filters - 4 inch thickness. Electrostatic charge captures airborne allergens SMALLER THAN 1 micron including fine dust, smoke, dander, mold, pet dander and dust mites. Also traps most large allergens including pollen and lint. Up to 20-times more effective at capturing micro particles than ordinary fiberglass filters. Designed for uniform air flow. Lasts UP TO 3 months. Will not support the growth of bacteria, mold, mildew or fungi in normal use. This product is listed and rated by Underwriters Laboratories as U.L. Class 2.