20" X 6" [Duct Opening] 2-Way Vertical Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 21.75"W X 7.75"H] Compatible With Duct 8in Actual Filter Size – 27

Actual Filter Size – 27 3/4"w x 33 3/4" x 1"

+ Product Details Size - 20"w X 18"h is the size for the duct opening measurement only

including Ductless Mini-Split

All of these grills have dampers

+ Product Details Size – 25"w X 36"h is the size for the duct opening measurement only

20" X 6" [Duct Opening] 2-Way Vertical Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 21.75"W X 7.75"H] Compatible With Duct 8in Actual Filter Size – 27+ Product Details Size 20"w X 6"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 21. 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