6"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 9.75"h] Copper Coil-Insulated Line Set Round-neck-to-square-face construction results in 360

Round-neck-to-square-face construction results in 360 degree air diffusion pattern similar to a full round diffuser

+ Product Details Size - 14"w X 18"h is the size for the duct opening measurement only

+ Product Details Perfect Fit & Easy Sizing - Designed for a 36" x 14" OR 14" x 36" duct opening (measured at the opening)

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

6"w X 8"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 9.75"h] Copper Coil-Insulated Line Set Round-neck-to-square-face construction results in 360+ Product Details Size 6"w X 8"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 7. 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