6"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 27.75"h] Ceiling + Product Details Size -

+ Product Details Size - 36"w X 12"h is the size for the duct opening measurement only

14" x 3" Decorative Wood Air Vent HVAC Duct Cover Grille - Polished Finish Red Oak Wood - 2-Way Air Direction

+ Product Details Size – 34"w X 20"h is the size for the duct opening measurement only

Actual Front End Outer Dimensions Are 16" Diameter

6"w X 26"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 27.75"h] Ceiling + Product Details Size -+ Product Details Size 6"w X 26"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 7. 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 wear