Accumulair Emerald is Economical, MERV 6 high-capacity media makes this filter an ideal upgrade from standard fiberglass throwaways. Captures a wide variety of airborne allergens including dust, mold, pet dander, and dust mites. Up to 8-times more effective at capturing micro particles than ordinary fiberglass filters. Excellent for high-velocity systems and maximum air flow. Heavy duty construction frame prevents airflow bypass. Lasts UP TO 3 months! Proudly made in USA.