Description
Actual dimensions are 20.75 x 20.75 x 4.38. Accumulair brand: 21x21x4.5 Rheem Protech 540018 style whole house air filters, specifically built to replace the original brand Rheem Protech 540018 air filters. Fully assembled - no assembly or combs required. MERV classified to ASHRAE ratings establishing particle filtration to the level of the original manufacturer Rheem Protech 540018 filters. Photo: Example air filter image as shown is not the actual dimensions and is there to show design only. OEM names and Rheem Protech 540018 P/N included for filter replacement purposes.