Product details:

Nominal size 20 x 20 x 5 (Actual size 19 3/4 x 19 3/4 x 4 3/8) Accumulair Filter for Honeywell model FC40R air filter # FC40R1003 Replaces Expandapac filter #FC35A1043 that was used in model F35R1002. What is MERV Great for reducing airborne particles such as dust, pollen, mold spores, tobacco smoke, pet dander, and particles that carry viruses. Superior frame strength utilizing double-wall construction and die-cut fingers. High-efficiency filter media collects small dust particles before they can collect on your coils. No assembly required. Easily inserts into and out of existing return grille. Allow a 7 depth behind the grille to provide space for the deeper filter and air flow through the filter. Made in the USA. Lasts up to 6 Months!