Actual Dimensions: 20 x 23.13 x .75. Accumulair brand 21x23.5x1 Trane TFE235A9AH30 substitute whole house air filters, specifically constructed to replace OEM Trane TFE235A9AH30 air filters. Completely assembled with no assembly or combs required. MERV classified to ASHRAE 52.2 test classifications assuring particulate filtration equal to the original manufacturer Trane TFE235A9AH30 air filter. Note: The example filter picture as shown is not the actual dimensions and is there to show construction purposes only. Brand names and Trane TFE235A9AH30 P/N are included for filter style identification use.