12"w X 12"h [Duct Opening] 4-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 13.75"H] Compatible With Duct 10in And The Cooler Air From

And The Cooler Air From Outside WIll Flow In From The Bottom

+ Product Details Size - 30"w X 18"h is the size for the duct opening measurement only

and the included installation screws make setup simple and efficient

+ Product Details Size – 16"w X 36"h is the size for the duct opening measurement only

12"w X 12"h [Duct Opening] 4-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 13.75"H] Compatible With Duct 10in And The Cooler Air From+ Product Details Size 12"w X 12"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" width X 13. 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