28" X 26" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 30 5/8" X 28 5/8"] 18" Round Duct Pipe By simply measuring the width

By simply measuring the width or the length of the vent

Plain Ends - Gives you the freedom to cut and flare at your own project needs

Actual Filter Size – 9 3/4"w x 11 3/4" x 1"

Actual Filter Size – 24 3/4"w x 33 3/4" x 1"

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

28" X 26" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 30 5/8" X 28 5/8"] 18" Round Duct Pipe By simply measuring the width+ Product Details Size 28"w X 26"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 30 5 8" width X 28 5 8" height Actual Filter Size 27 3 4"w x 25 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.