18" x 25" x 1", Naturalaire Standard Pleated Filter, Has An Ashrae 52.2 Rating Of Merv 8, Convenient To Use & Easy To Replace, Ordinary Furnace Filters Are Designed To Protect Heating & Cooling Equipment From The Insulating Properties Of Relatively Large Airborne Particles, Naturalaire Standard Goes Far Beyond That, Removing Even Those Microscopic Particles That Can Stain Walls & Furnishings, Or Worse, Aggravate Seasonal Allergies.
