12" X 12" Steel Return Air Filter Grille for 1" Filter - Removable Frame - * Filter Included *[Outer Dimensions: 14 5/8" X 14 5/8"] Insulated Line Simplified Installation: Our Butterfly Damper

Simplified Installation: Our Butterfly Damper ensures easy setup

actual front end outer dimensions are approximately 21

+ Product Details Size - 4"w X 20"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 22 5/8" width X 8 5/8" height

+ Product Details Size - 24"w X 4"h is the size for the duct opening measurement only

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