18" X 18" Steel Return Air Filter Grille for 1" Filter - Removable Frame - * Filter Included * [Outer Dimensions: 20 5/8" X 20 5/8"] fixed bar actual front end outer dimensions 75 Width X 17 LO3634 w20h20

actual front end outer dimensions are approximately 30 5/8" width X 36 5/8" height

+ Product Details Size - 14"w X 26"h is the size for the duct opening measurement only

+ Product Details Size - 36"w X 22"h is the size for the duct opening measurement only

/* more inner breathing room */ border-radius: 6px

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

18" X 18" Steel Return Air Filter Grille for 1" Filter Removable Frame * Filter Included * [Outer Dimensions: 20 5 8" X 20 5 8"] fixed bar actual front end outer dimensions 75 Width X 17 LO3634 w20h20 actual front end outer dimensions are approximately 30 5 8" width X 36 5 8" height + Product Details Size 14"w X 26"h is the size for the duct opening measurement only