Tier1 Replacement for Lennox 16x25x3 Merv 8 X0581 Air Filter 3 Pack Rated at MERV 8 to capture particles 3-10 microns in size Replacement for: Lennox X0581 and X5427 98% efficient filter media that captures small dust particles before they can collect on your coils This product is listed and rated by Underwriters Laboratories as U.L. Class 2