36"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace - Weather-Resistant Air Grille with Screen Mesh - Black [Outer Dimensions 37.75"w x 37.75"h] Insulated Line Set + Product Details Size - 4 X 12 Is CRFG2028 Width_14in

+ Product Details Size - 12"w X 8"h is the size for the duct opening measurement only

Actual Filter Size – 35 3/4"w x 33 3/4" x 1"

and slashes energy costs

actual front end outer dimensions are approximately 18 5/8" width X 12 5/8" height

Its sturdy construction guarantees a smooth

36"w X 36"h Aluminum Exterior Gable Louver Vent for Walls & Crawlspace Weather Resistant Air Grille with Screen Mesh Black [Outer Dimensions 37.75"w x 37.75"h] Insulated Line Set + Product Details Size 4 X 12 Is CRFG2028 Width_14in + Product Details Size 12"w X 8"h is the size for the duct opening measurement only Actual Filter Size – 35 3 4"w x 33 3 4" x 1"