Actual Size: 19.88 x 24.88 x 4.38. Accumulair brand 20x25x5 Honeywell F50A1066 substitute whole house air filters, exactly constructed to replace original brand Honeywell F50A1066 air filters. Fully constructed - no forming or combs required. MERV rated to ASHRAE classifications ensuring filtration as good or better than the name brand Honeywell F50A1066 filters. Photo: Sample air filter image shown is not to scale and is shown for design purposes only. Brand names and Honeywell F50A1066 P/N are used for air filter style purposes.