This is a replacement anti-allergy filter for Mitsubishi's MS-A09, MS-A12, and MFZ-KA mini split indoor units. Product Features Enzyme Catalyst Mitsubishi's anti-allergy filters capture allergens and use an enzyme catalyst to break them down, cleaning your air as it passes through the mini split indoor unit. Product Compatible With Mitsubishi MS-A09WA-1 Wall Mounted Mini Split Indoor Units Mitsubishi MS-A12WA-1 Wall Mounted Mini Split Indoor Units Mitsubishi MFZ-KA Floor Standing Mini Split Indoor Units