Tier1 Replacement for White-Rodgers 20x25x6 Merv 13 FR2000-401 Air Filter 2 Pack Upgraded media rated at MERV 13 to capture 90% of particles, 1 microns or smaller in size Replacement for: White-Rodgers FR2000-401 Superior frame strength utilizing double wall construction and die cut fingers This product is listed and rated by Underwriters Laboratories as U.L. Class 2