26"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 27.75"w x 23.75"h] return filter Filter Size - 5 4 X 12 Is CRFG2028 Width_14in

Filter Size - 5

+ Product Details Size – 18" x 24" or 24" x 18" is the size for the duct opening measurement only

while the included installation screws make setup quick and hassle-free

+ Product Details Perfect Fit & Easy Sizing - Designed for a 26" x 24" OR 24" x 26" duct opening (measured at the opening)

+ Product Details Size - 14"w X 12"h is the size for the duct opening measurement only

26"w X 22"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 27.75"w x 23.75"h] return filter Filter Size 5 4 X 12 Is CRFG2028 Width_14in Filter Size 5 + Product Details Size – 18" x 24" or 24" x 18" is the size for the duct opening measurement only