20"w X 32"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 33.75"h] Color_Anodized Aluminum Think of the diameter as CRFG2028 Width_14in 4 X 12 Is

Think of the diameter as a straight line from one end to the other

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 32" or 32" x 10" duct opening (measured at the opening)

+ Product Details Size – 8" x 20" or 20" x 8" is the size for the duct opening measurement only

+ Product Details Size – 25"w X 18"h is the size for the duct opening measurement only

high-impact plastic

20"w X 32"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 21.75"w x 33.75"h] Color_Anodized Aluminum Think of the diameter as CRFG2028 Width_14in 4 X 12 Is Think of the diameter as a straight line from one end to the other + Product Details Perfect Fit & Easy Sizing Designed for a 10" x 32" or 32" x 10" duct opening (measured at the opening)