24" X 28" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 26 5/8" X 30 5/8"] Adjustable Return + Product Details Size –

+ Product Details Size – 18"w X 24"h is the size for the duct opening measurement only

Actual Filter Size – 17 3/4"w x 33 3/4" x 1"

Design – Removable frame for easy filter change & cleaning - uses a 1" thick filter

+ Product Details Size - 36"w X 22"h is the size for the duct opening measurement only

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

24" X 28" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 26 5/8" X 30 5/8"] Adjustable Return + Product Details Size –+ Product Details Size 24"w X 28"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 26 5 8" width X 30 5 8" height Actual Filter Size 23 3 4"w x 27 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.