20"W X 22"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 21.75"W X 23.75"H] Color_White + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 12"w X 30"h is the size for the duct opening measurement only

+ Product Details Size – 8" x 20" or 20" x 8" is the size for the duct opening measurement only

Design – Unrestricted airflow For Your HVAC system - noise free components - no vibrating louvers etc

+ Product Details Size - 24"w X 36"h is the size for the duct opening measurement only

+ Product Details Size - 14"w X 22"h is the size for the duct opening measurement only

20"W X 22"H [Duct Opening] Steel Air Vent Return Grille HVAC VENT DUCT COVER DIFFUSER [Outer Dimensions: 21.75"W X 23.75"H] Color_White + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 12"w X 30"h is the size for the duct opening measurement only + Product Details Size – 8" x 20" or 20" x 8" is the size for the duct opening measurement only