Tier1 Replacement for Lennox 20x26x5 Merv 13 X0587 Air Filter 2 Pack Upgraded media rated at MERV 13 to capture 90% of particles, 1 microns or smaller in size Replacement for: Lennox X0587, ABC2000 and FR2000 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