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 at predicted low air motion

at predicted low air motion 35 fpm in the zone of occupancy

And One Towards The Bottom Of The Door

expanding or retracting the gap to meet your precise needs

actual front end outer dimensions are approximately 20 5/8" width X 28 5/8" height

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 at predicted low air motion+ 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