6"W X 20"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 7.75"W X 21.75"H] Ceiling 1/2" White insulation will give

1/2" White insulation will give you a good R value of 3

+ Product Details Size - 22"w X 6"h is the size for the duct opening measurement only

+ Product Details Size - 8"w X 30"h is the size for the duct opening measurement only

Some of the best features aren't readily apparent

Designed for optimal air flow and lasting durability

6"W X 20"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 7.75"W X 21.75"H] Ceiling 1/2" White insulation will give+ Product Details Size 6"w X 20"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 7. 75" width X 21. 75" height. Design Easy unrestricted airflow for your HVAC system 50 angled to provide maximum airflow. High Quality Solid stamped steel with counter sunk screw holes (screws included) and no sharp edges. Powder Coat Finish Smooth, shiny, scratch resistant, beautiful. Looks like it was just waxed.