10" Circular Round Aluminum HVAC Supply Grille Air Diffuser - With Butterfly Damper - Vent Duct Cover [Outer Dimensions: 12"] return filter + Product Details Size -

+ Product Details Size - 24"w X 22"h is the size for the duct opening measurement only

+ Product Details Size – 30"w X 20"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 16 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 20" duct opening (measured at the opening)

10" Circular Round Aluminum HVAC Supply Grille Air Diffuser - With Butterfly Damper - Vent Duct Cover [Outer Dimensions: 12"] return filter + Product Details Size -10" Diameter Is The Size For The Duct Opening Measurement Only, Actual Front End Outer Dimensions Are 10" Diameter Incorporated with Integral Butterfly Damper for full Airflow Control Assembeled Before Powder Coat Paint, to Ensure Perfect Smooth Finish Commercial Grade Aluminum Will Never Rust Designed for Warehouses, Factories, Workshops, Gymnasiums & Restaurants Center Core is Removable for Easy Access and Maintence 10" Circular Round Aluminum HVAC