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] Compatible With Duct 12in Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 16" X 16" duct openings

+ Product Details Size - 20"w X 30"h X 2"d (for duct opening measurement only)

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

actual front end outer dimensions are approximately 32 5/8" width X 32 5/8" height -

Complies with industry standards of USA: ASTM D-882

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] Compatible With Duct 12in Ideal for Walls & Ceilings:+ Product Details Size 20"w X 32"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 33. 75" Height Weather and Pest Proof These louvers are especially designed to prevent water from entering your home, and with a built in back 1 2" mesh they also protect you from annoying rodents like mice, rats, birds, and squirrels High Quality Aluminum The premium durable aluminum will never rust and it will never