32"W X 24"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 33.75"W X 25.75"H] Color_White Measure the size of the 4 X 12 Is CRFG2028 Width_14in

Measure the size of the vent opening

+ Product Details Size – 4"w X 14"h is the size for the duct opening measurement only

3 * Insulation density is 30kgs/CBM = 0

please note that the total outer dimensions of the grille measure 10" in diameter

+ Product Details Size - 25"w X 18"h is the size for the duct opening measurement only

32"W X 24"H [Duct Opening] Steel Air Vent Return Grille HVAC VENT DUCT COVER DIFFUSER [Outer Dimensions: 33.75"W X 25.75"H] Color_White Measure the size of the 4 X 12 Is CRFG2028 Width_14in Measure the size of the vent opening + Product Details Size – 4"w X 14"h is the size for the duct opening measurement only