This genuine Aprilaire 110 air filter replacement is rated MERV 11. That means it makes the air in your home fresh and healthy so your family can breathe easy. Its proven to prevent 92% of particles between 3 and 10 microns from passing through your homes heating and cooling system. That includes dust, pollen, and mold spores, which can irritate allergies and worsen asthma symptoms. Annual air filter replacements are a great way to keep your home and family protected. Aprilaire makes it easy-to- know what you are breathing.