6"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 7.75"w x 21.75"h] with filter + Product Details Size - 14" Round Duct Pipe For 10 duct opening FR M 414 White

+ Product Details Size - 8"w X 36"h is the size for the duct opening measurement only

preventing tampering and maintaining consistent temperature settings

+ Product Details Perfect Fit & Easy Sizing - Designed for a 10" x 20" duct opening (measured at the opening)

+ Product Details Size – 14"w X 24"h is the size for the duct opening measurement only

6"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 7.75"w x 21.75"h] with filter + Product Details Size 14" Round Duct Pipe For 10 duct opening FR M 414 White + Product Details Size 8"w X 36"h is the size for the duct opening measurement only preventing tampering and maintaining consistent temperature settings