34"w X 32"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 35.75"w x 33.75"h] 10" Diameter + Product Details Size – 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size – 30"w X 6"h is the size for the duct opening measurement only

or office environments

Actual Filter Size – 23 3/4"w x 29 3/4" x 1"

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

+ Product Details Size - 22"w X 10"h is the size for the duct opening measurement only

34"w X 32"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 35.75"w x 33.75"h] 10" Diameter + Product Details Size – 4 X 12 Is CRFG2028 Width_14in + Product Details Size – 30"w X 6"h is the size for the duct opening measurement only or office environments