12"W X 12"H [Duct Opening] 4-Way Aluminum Curved Blade Adjustable Air Supply HVAC Diffuser [Outer Dimensions: 13.75"W X 13.75"H] Powder Coated + Product Details Size -

+ Product Details Size - 12"w X 32"h is the size for the duct opening measurement only

The ring base allows installation without removing the thermostat

+ Product Details Size – 10" round duct opening-

+ Product Details Size - 20"w X 28"h is the size for the duct opening measurement only

12"W X 12"H [Duct Opening] 4-Way Aluminum Curved Blade Adjustable Air Supply HVAC Diffuser [Outer Dimensions: 13.75"W X 13.75"H] Powder Coated + Product Details Size -+ Product Details Size 12"w X 12"h is the size for the duct opening measurement only, actual front end outer dimensions are 13. 75" width X 13. 75" height. Design Individually adjusting curved blades for better air flow control. Screws Included High Quality Aluminum The premium durable aluminum will never rust and it will never wear through leaving the material with an elegant, beautiful, and smooth surface, adds a luxurious touch to any home.