8"W X 8"H [Duct Opening] 4-Way Aluminum Curved Blade Adjustable Air Supply HVAC Diffuser [Outer Dimensions: 9.75"W X 9.75"H] w28h28 + Product Details Size –

+ Product Details Size – 18"w X 16"h is the size for the duct opening measurement only

very easy to do

Actual Filter Size – 21 3/4"w x 11 3/4" x 1"

Horizontal blades in the front

actual front end outer dimensions are approximately 32 5/8" width X 16 5/8" height -

8"W X 8"H [Duct Opening] 4-Way Aluminum Curved Blade Adjustable Air Supply HVAC Diffuser [Outer Dimensions: 9.75"W X 9.75"H] w28h28 + Product Details Size –+ Product Details Size 8"w X 8"h is the size for the duct opening measurement only, actual front end outer dimensions are 9. 75" width X 9. 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. Carefully