10"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 29.75"h] 6" Diameter + Product Details Perfect Fit

+ Product Details Perfect Fit & Easy Sizing - Designed for a 36" x 20" OR 20" x 36" duct opening (measured at the opening)

10" x 4" Floor Register HVAC Air Supply Grille - Heavy Duty Rigid Built - Plastic Never Rust Vent Duct Cover

Actual Filter Size – 31 3/4"w x 31 3/4" x 1"

+ Product Details Size - 36"w X 4"h is the size for the duct opening measurement only

10"w X 28"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 29.75"h] 6" Diameter + Product Details Perfect Fit+ Product Details Size 10"w X 28"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 11. 75" Width X 29. 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