12"w X 6"h [Duct Opening] 1-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 7.75"H] Fixed Blades with Damper Universal Fit – Measures 6-1/4"

Universal Fit – Measures 6-1/4" wide x 4-3/4" high x 3" deep

actual front end outer dimensions are approximately 10 5/8" width X 18 5/8" height

Crafted from robust 20-gauge steel

+ Product Details Size - 40"w X 20"h is the size for the duct opening measurement only

12"w X 6"h [Duct Opening] 1-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 7.75"H] Fixed Blades with Damper Universal Fit – Measures 6-1/4"+ Product Details Size 12"w X 6"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" width X 7. 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