20"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 21.75"w x 21.75"h] 10" Round Duct Pipe Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 12" X 8" duct openings

actual front end outer dimensions are approximately 26 5/8" width X 38 5/8" height -

[Outer Dimensions: 20

Actual Front End Outer Dimensions Are 12" Width X 4" Height - SEE IN DESCRIPTION HOW TO MEASURE A GRILLE

20"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - White [Outer Dimensions 21.75"w x 21.75"h] 10" Round Duct Pipe Ideal for Walls & Ceilings:+ Product Details Size 20"w X 20"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 21. 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