Description
Actual size is 20.75 x 20.75 x 4.38. Accumulair brand: 21x21x4.5 Rheem PD540018 style whole house filters, exactly designed to be an alternative to the original brand Rheem PD540018 air filters. Fully constructed so no assembly or combs needed. MERV graded to ASHRAE 52.2 test specifications establishing particulate capture to the level of the name brand Rheem PD540018 air filter. Notice: The example air filter picture as displayed is not true to size and is shown for design purposes only. Brand names and Rheem PD540018 part numbers are listed for filter substitution identification use.