16" X 16" [Duct Opening] 3-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 17.75"W X 17.75"H] Round Damper Ring + Product Details Size –

+ Product Details Size – 22"w X 20"h is the size for the duct opening measurement only

+ Product Details Size – 28"w X 8"h is the size for the duct opening measurement only

Weather and Pest Proof – These louvers are especially designed to prevent water from entering your home

each diffuser is carefully shrink-wrapped with a sturdy cardboard backing

16" X 16" [Duct Opening] 3-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 17.75"W X 17.75"H] Round Damper Ring + Product Details Size –+ Product Details Size 16"w X 16"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 17. 75" width X 17. 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