10"w X 4"h [Duct Opening] 1-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 11.75"W X 5.75"H] w18h18 + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 36" or 36" x 12" duct opening (measured at the opening)

+ Product Details Size - 3" Diameter is the size for the duct opening measurement only

while the ingenious dial-controlled damper empowers you to effortlessly regulate airflow using your foot

And One Towards The Bottom Of The Door

10"w X 4"h [Duct Opening] 1-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 11.75"W X 5.75"H] w18h18 + Product Details Perfect Fit+ 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