Description
Actual Dimensions: 20.75 x 20.75 x 4.38. Brand: Accumulair. 21x21x4.5 Ruud Protech 540018 replacement whole house air filters, exactly designed to be an alternative to the name brand Ruud Protech 540018 air filters. Fully constructed so no assembly or combs needed. MERV graded to ASHRAE 52.2 test grades assuring operation as good or better than the name brand Ruud Protech 540018 air filter. Notice: Sample air filter image displayed is not true to size and is shown for design only. OEM names and Ruud Protech 540018 P/N shown for air filter replacement identification.