8"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 13.75"h] Curved Blade Steel + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 8" OR 8" x 30" duct opening (measured at the opening)

+ Product Details Size - 26"w X 4"h is the size for the duct opening measurement only

75" Width X 37

+ Product Details Size – 16" x 26" or 26" x 16" is the size for the duct opening measurement only

8"w X 12"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 13.75"h] Curved Blade Steel + Product Details Perfect Fit+ Product Details Size 8"w X 12"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 13. 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