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

+ Product Details Size - The listed 6" diameter refers specifically to the size of the duct opening

Complies with industry standards of USA: ASTM D-882

+ Product Details Size - 16"w X 26"h is the size for the duct opening measurement only

or just adding updated elements to your current home

Filter Size - 11

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