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 - 14" Round Duct Pipe For 10 duct opening FR M 414 White

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

+ Product Details Size - 16"w X 30"h X 2"d (for duct opening measurement only)

+ Product Details Size – 14" x 16" or 16" x 14" is the size for the 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 14" Round Duct Pipe For 10 duct opening FR M 414 White + Product Details Size 22"w X 18"h X 2"d (for duct opening measurement only) + Product Details Size 16"w X 30"h X 2"d (for duct opening measurement only)