10" X 4" [Duct Opening] 2-Way Vertical Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 11.75"W X 5.75"H] fixed bar With these options

With these options

actual front end outer dimensions are approximately 24 5/8" width X 32 5/8" height

+ Product Details Size - 8"w X 12"h is the size for the duct opening measurement only

+ Product Details Size - 18"w X 6"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 10 5/8" width X 38 5/8" height

10" X 4" [Duct Opening] 2-Way Vertical Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 11.75"W X 5.75"H] fixed bar With these options+ Product Details Size 10"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 11. 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