20"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 27.75"h] Color_Red Oak Wood Actual Filter Size – 17

Actual Filter Size – 17 3/4"w x 23 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 24" x 36" OR 36" x 24" duct opening (measured at the opening)

Actual Filter Size – 27 3/4"w x 15 3/4" x 1"

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 14" OR 14" x 20" duct opening (measured at the opening)

20"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 21.75"w x 27.75"h] Color_Red Oak Wood Actual Filter Size – 17+ Product Details Size 20"w X 26"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 21. 75" Width X 27. 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