Fantech HERO Air Exchanger Filter 428527 (2-PACK) 

• For an excellent air quality upgrade from the original MERV3 filters, consider the MERV8 replacement filters.
• This replacement filter kit features 2 pleated air filters with a MERV8 rating. Suitable for HERO 200H and HERO 250H Fresh Air Appliances.
• The filters will collect particles such as mold spores, pollen, cement dust, carpet fibers, debris, lint, and insects. With normal usage, it is recommended to replace the filter every 3 months.

NOTE: Upgrading to a more efficient filter will affect the airflow capability of your appliance.