20x20 Honeywell FC100A1011 air filter replacements are specifically designed to replace OEM 20x20 Honeywell FC100A1011 air filters.
They are rated to indpendent ANSI Honeywell FC100A1037 Filter F25F F35F F100F F200E 5pk features.
Efficiency ranges are defined for small particles, E1=0.3 to 1.0 microns; medium particles, E2=1.0 to 3.0 microns; and large particles, E3=3.0 to 10.0 microns