20"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 37.75"h] 1-Way + Product Details Size -

+ Product Details Size - 8"w X 36"h X 2"d (for duct opening measurement only)

+ Product Details Size – 24" x 24" with 8" collar T-Bar drop ceiling perforated return grill - metal back casing

+ Product Details Size - 32"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 10" x 18" or 18" x 10" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 27 5/8" width X 26 5/8" height

20"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 37.75"h] 1-Way + Product Details Size -+ Product Details Size 20"w X 36"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 37. 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