8"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 9.75"h] Round Damper Ring Filter Size - 23

Filter Size - 23

or office environments

Perfectly suited for both residential and commercial use

Actual Filter Size – 21 3/4"w x 27 3/4" x 1"

40"w X 16"h Is The Size For The Duct Opening Measurement Only

8"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 9.75"w x 9.75"h] Round Damper Ring Filter Size - 23+ Product Details Size 8"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 9. 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