36"W X 8"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 37.75"W X 9.75"H] Floor Grille + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 36"w X 6"h is the size for the duct opening measurement only

+ Product Details Size - 20"w X 30"h is the size for the duct opening measurement only

+ Product Details Size - 10"w X 18"h is the size for the duct opening measurement only

+ Product Details Size - 20"w X 34"h is the size for the duct opening measurement only

the decorative Victorian grill

36"W X 8"H [Duct Opening] Steel Air Vent Return Grille HVAC VENT DUCT COVER DIFFUSER [Outer Dimensions: 37.75"W X 9.75"H] Floor Grille + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 36"w X 6"h is the size for the duct opening measurement only + Product Details Size 20"w X 30"h is the size for the duct opening measurement only