Actual Dimensions: 20 x 23.13 x .75. Accumulair brand: 21x23.5x1 American Standard TFE235A9AH10 substitute whole house air filters, exactly built to substitute for the name brand American Standard TFE235A9AH10 air filters. Completely box-formed so no assembly or combs needed. MERV rated to ASHRAE classifications establishing performance as good or better than the OEM American Standard TFE235A9AH10 filter. Note: The sample air filter image as shown is not true to size and is there to show style purposes only. Company names and American Standard TFE235A9AH10 identifier displayed for filter replacement purposes only.