18" X 6" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 20 5/8" X 8 5/8"] ceiling + Product Details Size – actual front end outer LO246 Powder Coated

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

+ Product Details Size – 26"w X 12"h is the size for the duct opening measurement only

Actual Filter Size – 24 3/4"w x 35 3/4" x 1"

+ Product Details Size - 32"w X 28"h is the size for the duct opening measurement only

+ Product Details Size - 34"w X 30"h is the size for the duct opening measurement only

18" X 6" Steel Return Air Filter Grille for 1" Filter Removable Frame [Outer Dimensions: 20 5 8" X 8 5 8"] ceiling + Product Details Size – actual front end outer LO246 Powder Coated + Product Details Size – 8"w X 8"h is the size for the duct opening measurement only + Product Details Size – 26"w X 12"h is the size for the duct opening measurement only