8"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 19.75"h] Compatible With Duct 6in + Product Details Size -

+ Product Details Size - 36"w X 36"h X 2"d (for duct opening measurement only)

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

Insulation density is 30kgs/cbm = 0

+ Product Details Size - 34"w X 26"h is the size for the duct opening measurement only

8"w X 18"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 19.75"h] Compatible With Duct 6in + Product Details Size -+ Product Details Size 8"w X 18"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 19. 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 wear