Enjoy cleaner, fresher indoor air with the PureAir® HVAC MERV 11 Allergen Filter. This filter captures common allergens and other airborne particles such as pollen, household dust, dust mite debris, carpet fibers, lint, pet dander, smoke, smog and more. The filter traps 85% or more of airborne particles 3-10 micrometers in size.* 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. 16x25x1 filter is compatible with standard residentail furnace, air conditioner, or HVAC systems.