12"w X 6"h [Duct Opening] 3-Way Horizontal Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 7.75"H] Supply Grille + Product Details Size –

+ Product Details Size – 26"w X 22"h is the size for the duct opening measurement only

Actual Filter Size – 17 3/4"w x 7 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 36" or 36" x 8" duct opening (measured at the opening)

+ Product Details Size - 8"w X 6"h X 2"d (for duct opening measurement only)

12"w X 6"h [Duct Opening] 3-Way Horizontal Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 13.75"W X 7.75"H] Supply Grille + Product Details Size –+ 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