10"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 31.75"h] White + Product Details Size - d Product Details Size The 170B 16X16 FBA

+ Product Details Size - 26"w X 10"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 18 5/8" width X 32 5/8" height

Actual Filter Size – 23 3/4"w x 13 3/4" x 1"

rotate it to align with the square frame

+ Product Details Size - 10"w X 34"h is the size for the duct opening measurement only

10"w X 30"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 11.75"w x 31.75"h] White + Product Details Size d Product Details Size The 170B 16X16 FBA + Product Details Size 26"w X 10"h is the size for the duct opening measurement only actual front end outer dimensions are approximately 18 5 8" width X 32 5 8" height