Size:Single Pack (1) Product Description Air quality matters. That’s why you trust Aprilaire to keep your home environment safe for you and your family. This genuine Aprilaire 501 Air Filter Replacement is rated MERV 16. That means it makes the air in your home fresh and healthy so your family can breathe easy. It’s proven to prevent 98% of particles between 3.0 and 10.0 microns from passing through your home’s 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’re breathing From the Manufacturer The Aprilaire 501 is a MERV 10 air purifier replacement filter for the Aprilaire air cleaner 5000. The collapsible pleated fabric filter media is easily installed to keep your HVAC equipment running at top efficiency. Trade-marked Aprilaire Self-Seal technology ensures the best performance by reducing air bypass. Ultimately, this filter helps trap and reduce allergens that can cause persons afflicted with asthma and other respiratory problems anguish along with bacteria, dust, spores, pollen, pet dander, and more.