28"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 29.75"w x 23.75"h] Color_Black actual front end outer dimensions 4" Round Duct Pipe Product Details Size The SHEASC10W1-HP

actual front end outer dimensions are approximately 36 5/8" width X 24 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 24" or 24" x 12" duct opening (measured at the opening)

ready to enhance your space

The first number in a grille size

+ Product Details Size - The listed 12" diameter refers specifically to the size of the duct opening

28"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 29.75"w x 23.75"h] Color_Black actual front end outer dimensions 4" Round Duct Pipe Product Details Size The SHEASC10W1 HP actual front end outer dimensions are approximately 36 5 8" width X 24 5 8" height + Product Details Perfect Fit & Easy Sizing Designed for a 12" x 24" or 24" x 12" duct opening (measured at the opening)