6" X 18" or 18" x 6" Heavy Duty Floor Grille - Fixed Blades Air Grille - Brown [Outer Dimensions: 7.75 X 19.75] 5" Diameter + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 12"w X 34"h X 2"d (for duct opening measurement only)

+ Product Details Size & Compatibilty - The 12" to 6" round metal pipe reducer & increaser 30 gauge is compatible with duct 12" to 6"

We provide the best quality products

+ Product Details Size – 20"w X 50"h is the size for the duct opening measurement only

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

6" X 18" or 18" x 6" Heavy Duty Floor Grille Fixed Blades Air Grille Brown [Outer Dimensions: 7.75 X 19.75] 5" Diameter + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 12"w X 34"h X 2"d (for duct opening measurement only) + Product Details Size & Compatibilty The 12" to 6" round metal pipe reducer & increaser 30 gauge is compatible with duct 12" to 6"