Tier1 Replacement for Ultravation 16x25x5 Merv 8#91-005 Air Filter 2 Pack Rated at MERV 8 to capture particles 3-10 microns in size 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 This product is listed and rated by Underwriters Laboratories as U.L. Class 2