16"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 9.75"h] sidewall + Product Details Size -

+ Product Details Size - 22"w X 36"h is the size for the duct opening measurement only

+ Product Details Size – 24" x 24" with 14" collar T-Bar drop ceiling perforated return grill - metal back casing

Whether you're restoring an old Victorian or craftsman style home

Actual Filter Size – 27 3/4"w x 33 3/4" x 1"

+ Product Details Size – 28" x 36" or 36" x 28" is the size for the duct opening measurement only

16"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 17.75"w x 9.75"h] sidewall + Product Details Size -+ Product Details Size 16"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 17. 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