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 + Product Details Size -

+ Product Details Size - 28"w X 34"h is the size for the duct opening measurement only

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

These are airflow control components made to connect to supply grilles of the drop ceiling

actual front end outer dimensions are approximately 26 5/8" width X 16 5/8" height

With these options

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 + Product Details Size -+ 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