12" [Duct Opening] Round Ceiling Diffuser - Easy Air Flow - HVAC Vent Duct Cover [Black] - [Total Outer Dimensions: 16"] Compatible With Duct 6in Actual Filter Size – 21

Actual Filter Size – 21 3/4"w x 27 3/4" x 1"

actual front end outer dimensions are approximately 30 5/8" width X 10 5/8" height

with an additional 1 7/8" width and 2" height

rust-free aluminum construction with smooth finished edges and counter-sunk screw holes (screws included)

our Round Air Vent Supply Grille is the perfect addition

12" [Duct Opening] Round Ceiling Diffuser - Easy Air Flow - HVAC Vent Duct Cover [Black] - [Total Outer Dimensions: 16"] Compatible With Duct 6in Actual Filter Size – 21+ 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