Tier1 Replacement for White-Rodgers 20x26x5 Merv 11 F825-0549 Air Filter 2 Pack Upgraded media rated at MERV 11 to capture 90% of particles, 1-3 microns in size Replacement for: White-Rodgers F825-0549 and FR2000-100 Filter can also be used as a replacement filter for White-Rodgers electric air cleaner series SST20/SST2000 collection cell A811-0318/F811-0319 (Power must be disconnected when using a filter in place of a collection cell) This product is listed and rated by Underwriters Laboratories as U.L. Class 2