20"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 31.75"h] 10" Diameter + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 12" OR 12" x 20" duct opening (measured at the opening)

+ Product Details Perfect Fit & Easy Sizing - Designed for a 16" x 25" OR 25" X 16" duct opening (measured at the opening)

Insulation density is 30kgs/cbm = 0

+ Product Details Size – 25"w X 6"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 32" x 8" OR 8" x 32" duct opening (measured at the opening)

20"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 31.75"h] 10" Diameter + Product Details Perfect Fit+ Product Details Size 20"w X 30"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 31. 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