24" X 14" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 26 5/8" X 16 5/8"] 18in diameter + Product Details Size -

+ Product Details Size - 16"w X 18"h is the size for the duct opening measurement only

+ Product Details Size - 4"w X 16"h is the size for the duct opening measurement only

+ Product Details Size – 12"w X 20"h is the size for the duct opening measurement only

+ Product Details Size - 36"w X 6"h is the size for the duct opening measurement only

and Diffusers

24" X 14" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 26 5/8" X 16 5/8"] 18in diameter + Product Details Size -+ Product Details Size 24"w X 14"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 26 5 8" width X 16 5 8" height. High Quality high quality solid stamped steel with counter sunk screw holes (screws included) and no sharp edges Installation Location Ceiling Design Fixed hinged for easy filter change & cleaning uses a 1" thick filter. Our filter grille latch is easy to use on your fingers and