The FC40R Return Grille Filter is a high-efficiency, long-life replacement for return grille applications. It captures a significant amount of the airborne particles in the air that circulate through the filter. The FC40R features a special design that allows it to fit in the same space as a standard 1" return grille filter, while offering filtration that's up to forty times more effective (versus 1" fiberglass filters). The end result: thoroughly clean air down to 0.3 microns, you'll trap dust, pet dander, pollen, mold, bacteria and other allergens.

Honeywell FC40R return grille air cleaners fit most common brands of return grilles.