30"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 31.75"w x 21.75"h] Compatible With Duct 6in + Product Details Size – accordion content RFG2525 Black-HP 18" Round Duct Pipe

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

actual front end outer dimensions are approximately 31 5/8" width X 24 5/8" height -

+ Product Details Size – 16"w X 34"h is the size for the duct opening measurement only

listed size +1

The crank handle lever makes it easy to adjust to every weather situation

30"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 31.75"w x 21.75"h] Compatible With Duct 6in + Product Details Size – accordion content RFG2525 Black HP 18" Round Duct Pipe + Product Details Size – 30"w X 6"h is the size for the duct opening measurement only actual front end outer dimensions are approximately 31 5 8" width X 24 5 8" height