Honeywell FC100A1037 Filter F25F F35F F100F F200E-5pk Features: 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; medium particles, E2=1.0 to 3.0 microns; and large particles, E3=3.0 to 10.0 microns. Description 20X25 Media Air Filter Application Replacement Filter Dimensions (in.) 20 in. x 25 in.x 4in Dimensions (mm) 508 mm x 635 mm Efficiency Standard Efficiency ratings are based on American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 52.2-1999. Efficiency Standard 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. Fractional Efficiency E1=25%, E2=62%, E3=85% Minimum Efficiency Reporting Value (Media Filters Only) MERV 11 Static Pressure Drop (in. w.c.) 0.23 at 500 FPM Type or Air Cleaner Media Air Cleaner Can Be Used With Honeywell 20X25, 25X20, 25X22 F100 and F200 Media Air Cleaners, SpaceGard 2200