32"w X 34"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 33.75"w x 35.75"h] w26h26 + Product Details Perfect Fit 4 X 12 Is CRFG2028 Width_14in

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 22" OR 22" x 18" duct opening (measured at the opening)

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

High Quality – Solid rigid steel body for durability and reliability

+ Product Details Size - 20"w X 16"h is the size for the duct opening measurement only

32"w X 34"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 33.75"w x 35.75"h] w26h26 + Product Details Perfect Fit 4 X 12 Is CRFG2028 Width_14in + Product Details Perfect Fit & Easy Sizing Designed for a 18" x 22" OR 22" x 18" duct opening (measured at the opening) accordion header')