KEEP YOUR RZ AIRFLOW® PURIFYING FILTER AT TOP PERFORMANCE BY REPLACING THE HEPA FILTER AFTER 6 MONTHS OF CONTINUOUS USE ON AVERAGE. DESIGNED SPECIFICALLY FOR PTAC UNITS THE RZ AIRFLOW IS AFFORDABLE SIMPLE TO USE AND PURIFIES 99.97% OF THE AIR IN THE ROOM FROM VIRUSES ALLERGENS AND ODORS WITHIN 45 MINUTES ON AVERAGE. FEATURES UL STYLE""MARGIN-TOP0PX; PADDING-TOP 5PX; PADDING-BOTTOM 5PX;"" 6-MONTH FILTER LIFESPAN HEPA FILTER ELIMINATES UP TO 99.97% OF VIRUSES BACTERIA DUST PET DANDER POLLEN SMOKE AND ODORS. NO ADDED NOISE CREATED BY AIRFLOW WHILE OPERATING MINIMAL IMPACT TO THE PTAC UNIT AIRFLOW (5%) TOP-QUALITY AIR PURIFICATION COST EFFECTIVE SOLUTION SET IT & FORGET IT