Description
Actual size is 20.75 x 20.75 x 4.38. Accumulair brand 21x21x4.5 Rheem PD540012 compatible whole house air filters, specifically engineered to replace the name brand Rheem PD540012 filters. Fully assembled - no forming or combs required. MERV rated to ASHRAE standards establishing performance equal to the original brand Rheem PD540012 filter. Note: Example filter picture displayed is not the actual dimensions and is included to show style only. Brand names and Rheem PD540012 P/N used for filter replacement purposes.