This filter is convenient to use and easy to replace. Ordinary furnace filters are designed to protect heating and cooling equipment from the insulating properties of relatively large airborne particles. The NaturalAire Standard goes far beyond that removing even those microscopic particles that can stain walls and furnishings or worse aggravate seasonal allergies. 10 x 10 x 1 The NaturalAire Standard has an ASHRAE 52.2 rating of MERV 8 Standard pleated furnace filters Made of a 1 sided metal reinforced pleated media recyclable clay coated moisture resistant frame Captures particles as small as 1 microns and is effective against the following contaminants pet dander mold spores dust mite debris pollen household dust debris and lint Last up to 90 days.