Accord ABRGWH106 Return Grille with 1/2-Inch Fin Louvered, 10-Inch x 6-Inch(Duct Opening Measurements), White,Accord,ABRGWH106" /> Measure the duct opening to determine the correct size, not the outside of the grille Listed product size refers to the duct opening measurements Steel construction with 1/2-in spaced fins For wall or ceiling application 10-in x 6-in is the size of the duct opening dimensions, the grille itself measures 11.8-in X 7.8-in