12" [Duct Opening] Round Ceiling Diffuser - Easy Air Flow - HVAC Vent Duct Cover [Black] - [Total Outer Dimensions: 16"] 8" Diameter our grill boasts an impressive

our grill boasts an impressive 96% airflow capacity

listed size +2"

40"w X 16"h Is The Size For The Duct Opening Measurement Only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 24" OR 24" x 18" duct opening (measured at the opening)

12" [Duct Opening] Round Ceiling Diffuser - Easy Air Flow - HVAC Vent Duct Cover [Black] - [Total Outer Dimensions: 16"] 8" Diameter our grill boasts an impressive+ Product Details Size The listed 12" diameter refers specifically to the size of the duct opening. However, please note that the total outer dimensions of the grille measure 16" in diameter. Design Heavier gauge than needed, built for durability and long life in mind, but still light and handy. (Screws included). Airflow Easy unrestricted airflow for your HVAC system. Powder Coat Finish Smooth, shiny, scratch resistant, beautiful. Looks like it was