12"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 11.75"h] 8" Round Duct Pipe actual front end outer dimensions

actual front end outer dimensions are approximately 14 5/8" width X 10 5/8" height

Actual Filter Size – 9 3/4"w x 33 3/4" x 1"

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+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 20" OR 20" x 18" duct opening (measured at the opening)

High Quality – High-quality rust-free

12"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 11.75"h] 8" Round Duct Pipe actual front end outer dimensions+ Product Details Size 12"w X 10"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 75" Width X 11. 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