36"W X 14"H [Duct Opening] ALUMINUM RETURN GRILLE - Easy Air Flow - Linear Bar Grilles [Outer Dimensions: 31.875"W X 7.875"H] Access Door + Product Details Size – 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size – 24"w X 24"h is the drop ceiling HVAC supply grille size - for T-Bar lay-in

+ Product Details Size – 12"w X 26"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 20 5/8" width X 18 5/8" height

Width vs Height:

actual front end outer dimensions are approximately 32 5/8" width X 18 5/8" height

36"W X 14"H [Duct Opening] ALUMINUM RETURN GRILLE Easy Air Flow Linear Bar Grilles [Outer Dimensions: 31.875"W X 7.875"H] Access Door + Product Details Size – 4 X 12 Is CRFG2028 Width_14in + Product Details Size – 24"w X 24"h is the drop ceiling HVAC supply grille size for T Bar lay in + Product Details Size – 12"w X 26"h is the size for the duct opening measurement only