12" X 4" [Duct Opening] 3-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 5.75"H] fixed bar Made of high quality aluminum

Made of high quality aluminum that will never rust

actual front end outer dimensions are approximately 27 5/8" width X 28 5/8" height

+ Product Details Size - 16"w X 24"h is the size for the duct opening measurement only

then you'll need a 14-inch round vent

12" X 4" [Duct Opening] 3-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 5.75"H] fixed bar Made of high quality aluminum+ Product Details Size 12"w X 4"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 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