21x21x4.5 Rheem Protech 540018 Air Filter

Actual dimensions are 20.75 x 20.75 x 4.38. Accumulair brand, 21x21x4.5 Rheem Protech 540018 style whole house air filters, exactly constructed to be an alternative to the name brand Rheem Protech 540018 filters. Fully box-formed so no forming or combs required. MERV classified to ASHRAE grades establishing particle capture to the level of the original manufacturer Rheem Protech 540018 air filters. Photo: The example filter image as displayed is not the actual dimensions and is displayed for style purposes only. Brand names and Rheem Protech 540018 part numbers used for filter substitution identification purposes only.