8"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 31.75"h] Supply Grille + Product Details Size –

+ Product Details Size – 20"w X 14"h is the size for the duct opening measurement only

With a solid base for stability

Actual Filter Size – 27 3/4"w x 7 3/4" x 1"

with actual outer dimensions of 28

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 28" OR 28" x 26" duct opening (measured at the opening)

8"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 31.75"h] Supply Grille + Product Details Size –+ Product Details Size 8"w X 30"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 75" Width X 31. 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