18"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 19.75"w x 37.75"h] w16h16 reducing energy costs and maximizing 4 X 12 Is CRFG2028 Width_14in

reducing energy costs and maximizing HVAC system lifespan

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 8" or 8" x 12" duct opening (measured at the opening)

Rigid Built For External Use– The sturdy and rigid design features noise free components that eliminates vibration and excess noise to the louvers

+ Product Details Size – 20"w X 22"h is the size for the duct opening measurement only

+ Product Details Size - 14"w X 34"h X 2"d (for duct opening measurement only)

18"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 19.75"w x 37.75"h] w16h16 reducing energy costs and maximizing 4 X 12 Is CRFG2028 Width_14in reducing energy costs and maximizing HVAC system lifespan + Product Details Perfect Fit & Easy Sizing Designed for a 12" x 8" or 8" x 12" duct opening (measured at the opening)