The Return Grille Filter provides high efficiency, long life alternative to a 1" filter. It captures a significant amount of the airborne particles in the air that circulates through the filter.  Generic FC40R1011

Description                   20X25 Return Grill Media Air Filter

Application                   Return Grill

Dimensions (in.)            20 in. x 25 in.

Actual Size                   19 ¾” x 24 ¾” x 4 3/8”

Airflow Max.-Capacity (cfm)                1150 cfm

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=31%, E2=61%, E3=86%

Minimum Efficiency Reporting Value (Media Filters Only)                     MERV 8