10"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - [Outer Dimensions 11.75"w x 21.75"h] 8" Diameter and extends HVAC system life 4 X 12 Is CRFG2028 Width_14in

and extends HVAC system life

+ Product Details Size – 8"w X 18"h is the size for the duct opening measurement only

+ Product Details Size – 36"w X 32"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 38 5/8" width X 34 5/8" height

Actual Filter Size – 24 3/4"w x 23 3/4" x 1"

10"w X 20"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh [Outer Dimensions 11.75"w x 21.75"h] 8" Diameter and extends HVAC system life 4 X 12 Is CRFG2028 Width_14in and extends HVAC system life + Product Details Size – 8"w X 18"h is the size for the duct opening measurement only