4"W X 16"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 5.75"W X 17.75"H] Aluminum 5" - SEE BELOW IN

5" - SEE BELOW IN DESCRIPTION How To Measure A Grille

Pre-flared ends with nuts are for simple and easy installation

You may think of grilles and registers as a generic component of the ventilation system in your house

+ Product Details Size – 10" x 30" or 30" x 10" is the size for the duct opening measurement only

Design – Unrestricted airflow for your HVAC system - adjustable one-way louver with full horizontal airflow directional control - single deflection supply grill with 96% airflow - noise free components - no vibrating louvers etc

4"W X 16"H [Duct Opening] Steel Air Vent Return Grille - HVAC VENT DUCT COVER DIFFUSER - [Outer Dimensions: 5.75"W X 17.75"H] Aluminum 5" - SEE BELOW IN+ Product Details Size 4"w X 16"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 5. 75" width X 17. 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.