10"w X 8"h [Duct Opening] 3-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 11.75"W X 9.75"H] 3-Way or 4-Way + Product Details Size –

+ Product Details Size – 16" x 20" or 20" x 16" is the size for the duct opening measurement only

Actual Filter Size – 33 3/4"w x 15 3/4" x 1"

+ Product Details Size - 18"w X 8"h is the size for the duct opening measurement only

With HVAC Premium you get an extra measure of quality that will be visible to your family members and house guests

10"w X 8"h [Duct Opening] 3-Way Fixed Curved Blade Air Supply Diffuser Register Vent Cover Grille [Outer Dimensions: 11.75"W X 9.75"H] 3-Way or 4-Way + Product Details Size –+ Product Details Size 10"w X 8"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 11. 75" width X 9. 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