12"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 29.75"h] 6" Diameter + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 24"w X 36"h is the size for the duct opening measurement only

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 4" duct openings

+ Product Details Size - 12"w X 4"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 34" x 36" OR 36" x 34" duct opening (measured at the opening)

Say goodbye to pest-related worries as the built-in back 1/2" mesh acts as a barrier against unwanted rodents like mice

12"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 13.75"w x 29.75"h] 6" Diameter + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 24"w X 36"h is the size for the duct opening measurement only Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 4" duct openings