Odor Removal Plus MERV 8 Air Filter in 4 Pack of Furnace Filters Case of 4 Safe Home TM brand air purifier filters, a year's worth for most families. For a cleaner home, replace standard disposable furnace filter or washable metal furnace filter with this 16 inch by 20 inch by 1 inch dual f urnace filter insert with MERV 8 rating. One inch home air replacement filter captures allergens, odors, and harmful chemicals. The Duo has self sealing edges to maximize effectiveness at capturing allergens, odors, and chemicals from home air. Use for furnace filter slots, temporary needs, or custom sizes in air return grills. Duo replaces any 1 thick home air filter in any location and can last up to 3 months. Always check with your HVAC technician before changing from your current furnace filter. This unit is a MERV 8. Made in USA. Or use the Duo air purifier in your return air vent grille. Just open the door. Remove the one inch filter and slip in your new gas and particulate air filter unit. Close the door. Cleaner air is on its way. How does the Duo work? The 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 16 x 20 x 1 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 MER This item ships from a separate warehouse and may require extra time for delivery.