36"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 9.75"h] Material_Steel + Product Details Size –

+ Product Details Size – 30"w X 22"h is the size for the duct opening measurement only

Actual Filter Size – 9 3/4"w x 31 3/4" x 1"

actual front end outer dimensions are approximately 28 5/8" width X 28 5/8" height

+ Product Details Size - 20"w X 18"h X 2"d (for duct opening measurement only)

very easy to do

36"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 9.75"h] Material_Steel + Product Details Size –+ Product Details Size 36"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 37. 75" Width X 9. 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