18"w X 24"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 19.75"w x 25.75"h] 12in diameter + Product Details Size – Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

+ Product Details Size – 14" x 16" or 16" x 14" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 30 5/8" width X 30 5/8" height

See our separate listing for Butterfly Dmaper to Control Airflow

+ Product Details Size - 22"w X 18"h X 2"d (for duct opening measurement only)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 22" OR 22" x 20" duct opening (measured at the opening)

18"w X 24"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh Black [Outer Dimensions 19.75"w x 25.75"h] 12in diameter + Product Details Size – Compatible With Duct 7in Applications This sheet metal DDAG A 1212 + Product Details Size – 14" x 16" or 16" x 14" is the size for the duct opening measurement only actual front end outer dimensions are approximately 30 5 8" width X 30 5 8" height