12" X 24" ALUMINUM RETURN FILTER GRILLE FOR 1" FILTER - EASY AIRFLOW - LINEAR BAR GRILLES Color_Red Oak + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 36"w X 8"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18

+ Product Details Size – 10" x 30" or 30" x 10" is the size for the duct opening measurement only

The first number in a grille size represents the width

actual front end outer dimensions are approximately 18 5/8" width X 12 5/8" height

12" X 24" ALUMINUM RETURN FILTER GRILLE FOR 1" FILTER EASY AIRFLOW LINEAR BAR GRILLES Color_Red Oak + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 36"w X 8"h is the size for the duct opening measurement only actual front end outer dimensions are approximately 18