Tier1 Replacement for GeneralAire 16x25x3 Merv 13 14164 & 4521 Air Filter 3 Pack Upgraded media rated at MERV 13 to capture 90% of particles, 1 microns or smaller in size Replacement for: GeneralAire 14164, 3FM1625, 4521, Trion / Air Bear 255649-101, 229990-101, Quality Filters SBTRABC40 and SBTRABCMQP 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