36"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 17.75"h] return grille + Product Details Size -

+ Product Details Size - 34"w X 18"h is the size for the duct opening measurement only

For 14" Round Duct Opening - Spiral or Flex

actual front end outer dimensions are approximately 16 5/8" width X 18 5/8" height

Air Flow – Ensure a quiet and smooth HVAC system with noise-free components

10"w X 2"h Is The Size For The Duct Opening Measurement Only

36"w X 16"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 37.75"w x 17.75"h] return grille + Product Details Size -+ Product Details Size 36"w X 16"h X 2"d (for duct opening measurement only); actual front end outer dimensions are 37. 75" Width X 17. 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