Description
Actual Size: 20.75 x 20.75 x 4.38. Brand: Accumulair. 21x21x4.5 Rheem Protech 540018 substitute whole house air filters, exactly constructed to be an alternative to the name brand Rheem Protech 540018 filters. Completely box-formed so no assembly or combs required. MERV rated to ASHRAE 52.2 test specifications assuring particle capture to the level of the name brand Rheem Protech 540018 air filters. Photo: Example filter pic shown is not the actual dimensions and is shown for design only. Trade names and Rheem Protech 540018 identifier used for filter style identification only.