12" X 6" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 14 5/8" X 8 5/8"] w25h25 Its smooth

Its smooth

Actual Filter Size – 11 3/4"w x 5 3/4" x 1"

+ Product Details Size – 12"w X 14"h is the size for the duct opening measurement only

Actual Filter Size – 23 3/4"w x 17 3/4" x 1"

+ Product Details Size - 4"w X 10"h is the size for the duct opening measurement only

12" X 6" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 14 5/8" X 8 5/8"] w25h25 Its smooth+ Product Details Size 12"w X 6"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 14 5 8" width X 8 5 8" height Actual Filter Size 11 3 4"w x 5 3 4" x 1" High quality High quality solid stamped steel with counter sunk screw holes (screws included) and no sharp edges Location Sidewall and ceiling Design Removable door face for easy filter change & cleaning uses a 1" thick filter. Our filter grille