The Aprilaire 213 Air Purifier Replacement Filter by Tier1 (2-Pack) is a high performance MERV 13 air purifier replacement filter for Aprilaire model air cleaners 1210, 2210, 3210, and 4200. 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, when compared to the 210, helps trap and reduce even more allergens that can cause issues for persons afflicted with asthma and other respiratory problems. The Aprilaire 213 Air Purifier Replacement Filter by Tier1 (2-Pack) specifically reduces bacteria, dust, spores, pollen, pet dander, and more. Order today!