Honeywell FC100A1037 20 x 25 x 5 MERV 11 Filter Media, 5 Pack by Honeywell
- Efficiency ratings are based on American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 52.2 1999. Efficiency ranges are defined for small particles, E1=0.3 to 1.0 microns.
- and large particles, E3=3.0 to 10.0 microns..