Tier1 Replacement for Lennox 16x26x5 Merv 11 AC Furnace Air Filter 2 Pack Upgraded media rated at MERV 11 to capture 90% of particles, 1-3 microns in size Replacement for: Lennox X0584 High efficiency filter media collects small dust particles before they can collect on your coils This product is listed and rated by Underwriters Laboratories as U.L. Class 2