30"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 31.75"w x 31.75"h] Round Damper Ring + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 26"w X 16"h is the size for the duct opening measurement only

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

+ Product Details Size – 10"w X 14"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 36 5/8" height

ensuring consistent temperature control

30"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 31.75"w x 31.75"h] Round Damper Ring + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 26"w X 16"h is the size for the duct opening measurement only + Product Details Size – 12"w X 4"h is the size for the duct opening measurement only