8" X 4" [Duct Opening] 2-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 9.75"H X 5.75"H] 14" Diameter + Product Details Size –

+ Product Details Size – 12" x 30" or 30" x 12" is the size for the duct opening measurement only

Adjustable airflow control – Adjustable airflow control: The system allows users to customize the amount of air supply

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

9% Pure Copper meeting ASTM B280 standards

+ Product Details Size - 34"w X 20"h is the size for the duct opening measurement only

8" X 4" [Duct Opening] 2-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 9.75"H X 5.75"H] 14" Diameter + Product Details Size –+ Product Details Size 8"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 9. 75" width X 5. 75" height. High Quality High quality steel with counter sunk screw holes (screws included) and no sharp edges. Equipped with a lever for easy airflow adjustment and dampening. Airflow Control Adjustable airflow lever allows precise control over the direction and volume of air. Installation Location