12" X 24" Steel Return Air Filter Grille for 1" Filter - Removable Frame - * Filter Included * [Outer Dimensions: 14 5/8" X 26 5/8"] w28h28 + Product Details Size -

+ Product Details Size - 28"w X 8"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 12 5/8" width X 32 5/8" height -

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

actual front end outer dimensions are approximately 20 5/8" width X 8 5/8" height

By simply measuring the width or the length of the vent

12" X 24" Steel Return Air Filter Grille for 1" Filter - Removable Frame - * Filter Included * [Outer Dimensions: 14 5/8" X 26 5/8"] w28h28 + Product Details Size -+ Product Details Size 12"w X 24"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 14 5 8" width X 26 5 8" height Actual Filter Size 11 3 4"w x 23 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.