34"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 11.75"h] w36h36 /* Slightly darker color for 4 X 12 Is CRFG2028 Width_14in

/* Slightly darker color for better readability */ }

+ Product Details Perfect Fit & Easy Sizing - Designed for a 8" x 22" or 22" x 8" duct opening (measured at the opening)

How To Measure A Floor Register

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

+ Product Details Size – 20" x 22" or 22" x 20" is the size for the duct opening measurement only

34"w X 10"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 35.75"w x 11.75"h] w36h36 * Slightly darker color for 4 X 12 Is CRFG2028 Width_14in * Slightly darker color for better readability * } + Product Details Perfect Fit & Easy Sizing Designed for a 8" x 22" or 22" x 8" duct opening (measured at the opening)