12"W X 12"H [Duct Opening] Never Rust Plastic 4-Way-Vertical Air Supply Register - HVAC Vent Duct Grille - Off White [Outer Dimensions: 13.75"W X 13.75"H] 8in diameter + Product Details Size -

+ Product Details Size - 20"w X 28"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 24"h is the size for the duct opening measurement only

of up to 300m3/h

actual front end outer dimensions are approximately 16 5/8" width X 34 5/8" height

Actual Front End Outer Dimensions Are 14" Width X 8" Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE

12"W X 12"H [Duct Opening] Never Rust Plastic 4-Way-Vertical Air Supply Register - HVAC Vent Duct Grille - Off White [Outer Dimensions: 13.75"W X 13.75"H] 8in diameter + Product Details Size -+ Product Details Size 12"w X 12"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 13. 75" width X 13. 75" height. Design Rigid gauge ABS plastic. Rigid gauge built for durability and long life in mind, but still light and handy. Powder coat finish. Smooth, scratch resistant, beautiful. Looks like new after years of use. Screws Included High Quality High quality ABS plastic will never rust, no