34"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 37.75"h] ceiling actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in

actual front end outer dimensions are approximately 18 5/8" width X 28 5/8" height

+ Product Details Size - 10"w X 12"h X 2"d (for duct opening measurement only)

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

+ Product Details Size - 28"w X 6"h is the size for the duct opening measurement only

listed size +2"

34"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 35.75"w x 37.75"h] ceiling actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in actual front end outer dimensions are approximately 18 5 8" width X 28 5 8" height + Product Details Size 10"w X 12"h X 2"d (for duct opening measurement only)