Tier1 Replacement for GeneralAire 16x25x5 Merv 13 14161 & 4511 Air Filter 2 Pack Upgraded media rated at MERV 13 to capture 90% of particles, 1 microns or smaller in size Replacement for: GeneralAire 14161, 5FM1625, 4511, Skuttle #000-0448-001, Trion / Air Bear 255649-105, 229990-105 and 259112-101 General has started rounding the dimensions on their 5-inch filters. These filters still fit the same, they just no longer contain fractions in the description This product is listed and rated by Underwriters Laboratories as U.L. Class 2