16"w X 16"h 4-Way Aluminum Curved Blade Adjustable Air Supply HVAC Diffuser - Full Control Vertical/Horizontal Airflow Direction - Vent Duct Cover Outer Dimensions: 17.65"w X 17.65"h

16"w X 16"h Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 17.65" Width X 17.65" Height - SEE BELOW IN DESCRIPTION HOW TO MEASURE A GRILLE,Never Rust - High Quality Rigid Aluminum,4-Way Adjustale Louvers - Full Control Vertical/Horizontal Airflow Direction,Rigid Design - Noise Free Components - No Vibrating Louvers Etc.,replacement-furnace-filters Never Rust - High Quality Rigid Aluminum|4-Way Adjustale Louvers - Full Control Vertical/Horizontal Airflow Direction|Rigid Design - Noise Free Components - No Vibrating Louvers Etc.|replacement-furnace-filters