12"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 13.75"w x 15.75"h] w6h6 + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 24"w X 12"h is the size for the duct opening measurement only

One model suits both T-Bar and Drywall installations

+ Product Details Size - 36"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 8" x 18" or 18" x 8" is the size for the duct opening measurement only

+ Product Details Size – 34"w X 6"h is the size for the duct opening measurement only

12"w X 14"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 13.75"w x 15.75"h] w6h6 + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 24"w X 12"h is the size for the duct opening measurement only One model suits both T Bar and Drywall installations