18" X 26" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 20 5/8" X 28 5/8"] Powder-Coat this flex duct decreases the

this flex duct decreases the pressure loss and provides a more hygienic environment

+ Product Details Size – 20"w X 34"h is the size for the duct opening measurement only

Design – Fixed Hinged for easy filter change & cleaning - uses a 1" thick filter

the actual front end outer dimensions are 10" in diameter

+ Product Details Size - 36"w X 24"h is the size for the duct opening measurement only

18" X 26" Steel Return Air Filter Grille for 1" Filter - Removable Frame - [Outer Dimensions: 20 5/8" X 28 5/8"] Powder-Coat this flex duct decreases the+ Product Details Size 18"w X 26"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 20 5 8" width X 28 5 8" height Actual Filter Size 17 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.