Product Description The NaturalAire Pre-Pleat 40 Charcoal air filter offers high filtration to protect your HVAC system and indoor air against particulates and odors while also minimizing air pressure drop off to keep your system running at peak efficiency. The NaturalAire Pre-Pleat 40 Charcoal air filter is best used as a pre-filter or for heavy-duty commercial, industrial or pharmaceutical applications where high dust holding is required. The NaturalAire Pre-Pleat 40 Charcoal air filter is suitable for a wide variety of HVAC systems and holds a MERV (Minimum Efficiency Reporting Value) rating of 6, which means it is third-party certified to effectively reduce indoor dust and particle debris. MERV ratings provide a standard comparison of air filter performance. A higher MERV rating signifies greater efficiency and increased protection against airborne particles. Breathe easy knowing that AAF Flanders provides the best quality product to keep your indoor air pure. From the Manufacturer Flanders NaturalAire PrePleat MERV 6 utilizes the latest technology in fine mesh activated carbon. It is formulated to increase the attraction and capture of pet and human odors, as well as other common household contaminants that are known to aggravate allergies.