12"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 27.75"h] Color_White R value rating of insulation

R value rating of insulation - r3

Wall & Ceiling Applications

actual front end outer dimensions are approximately 23

actual front end outer dimensions are approximately 20 5/8" width X 36 5/8" height

12"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 27.75"h] Color_White R value rating of insulation+ Product Details Size 12"w X 26"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 13. 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