20"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 15.75"h] Powder Coated Actual Filter Size – 11

Actual Filter Size – 11 3/4"w x 15 3/4" x 1"

Experience enhanced indoor comfort with our 6" Butterfly Damper

+ Product Details Size - 30"w X 20"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 34"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 8" OR 8" x 28" duct opening (measured at the opening)

20"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 15.75"h] Powder Coated Actual Filter Size – 11+ Product Details Size 20"w X 14"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 15. 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