36" X 28" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 38 5/8" X 30 5/8"] 10" Round Duct Pipe actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in

actual front end outer dimensions are approximately 26 5/8" width X 32 5/8" height

+ Product Details Size - 22"w X 4"h is the size for the duct opening measurement only

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

actual front end outer dimensions are approximately 38 5/8" width X 8 5/8" height

It comes with two versatile mounting base options—solid and ring—making installation simple and flexible

36" X 28" Steel Return Air Filter Grille for 1" Filter Removable Frame [Outer Dimensions: 38 5 8" X 30 5 8"] 10" Round Duct Pipe actual front end outer dimensions 4 X 12 Is CRFG2028 Width_14in actual front end outer dimensions are approximately 26 5 8" width X 32 5 8" height + Product Details Size 22"w X 4"h is the size for the duct opening measurement only