Disposable Furnace Filter for 24 x 24 Slot Has Self-Seal Edges so All Air is Filtered The Safe Home TM Duo replacement furnace filter differs from a standard disposable furnace filter for a 24 inch by 24 inch by 1 inch filter slot. Note Check with your HVAC technician to verify that your system is able enough to handle the density of a MERV 8 filter before purchasing this or any other MERV 8 filter. Install this MERV 8 with Air Flow First Going through the White Media. Made in USA. MERV 8 disposable air purifier filter for furnaces with one inch slots captures allergens, odors, and harmful chemicals. Self sealing edges maximize effectiveness at capturing allergens, odors, and chemicals from your home's air. Use for furnace filter slots, temporary needs, or custom sizes in air return grills. The Duo replaces any 1 thick home air filter in any location and can last up to 3 months. How does the Duo work? Polyester outer layers remove pollen, mold spores, and other common allergens. The inner layer features FormaldaSorb TM and activated carbon that traps a variety of odors and hazardous gasses, such as formaldehyde, ammonia, and others that are emitted by cleaning chemicals, paint, particle board, and other household items. No other filters are as effective at removing dust mites, mold spores, pollen, odors, cleaning chemicals, ozone, paint fumes, and common gasses like formaldehyde which triggers asthma and allergies. Safe Home Duo Filter Features Dimensions 24 x 24 x 1 Internal Frame self-sealing edges. Captures up to 95% of common household allergens Eliminates odors from pets, paint, cooking, and more FormaldaSorb TM , a patented potassium permanganate product plus the activated carbon in the second layer of the filter trap gasses that can cause health issues. Highly effective and affordable. 2 stage air filter one MERV 8 rated polyester white allergen filter plus the activated carbon filter pad. Made in USA. Change the Duo at least