16" X 16" [Duct Opening] 4-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 17.75"W X 17.75"H] with filter The crank handle lever makes

The crank handle lever makes it easy to adjust to every weather situation

+ Product Details Size – 26"w X 12"h is the size for the duct opening measurement only

thanks to counter-sunk screw holes and included screws

+ Product Details Size - 36"w X 18"h is the size for the duct opening measurement only

Think of the diameter as a straight line from one end to the other

16" X 16" [Duct Opening] 4-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 17.75"W X 17.75"H] with filter The crank handle lever makes+ 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