Enjoy cleaner, fresher indoor air with the PureAir® MERV 11 Premium Allergen Air Filter. This filter captures unwanted allergens and helps maintain optimal airflow in your home, filtering out airborne particles such as pollen, household dust, dust mite debris, carpet fibers, lint, pet dander, smoke, smog and more. A pleated design, electrostatic dual wire backing, and air flow indicator arrow provides high performance and simple installation. For best performance, replace every 3 months. 20x20x1 filter is compatible with standard residential furnace, air conditioner, or HVAC systems.