Roof Curb, For Fan Base Size 39 in, Curb Height 12 in, Curb Inside Width 34 1/2 in, Curb Outside Width 37 1/2 in, Material Steel, Standards UL 705, For Use With 39 in Square Base, Adjustability Fixed, Ventilation Type Nonventilated, Application General Exhaust, Curb Inside Length 34.5, Curb Outside Length 37 1/2 in, Curb Shape Square, Features Flashing Flange, One Welded Corner, Wood Nailer, Finish Galvanized, Flashing Flange Width 2 in. This item has been restricted from sale in the following state (s): []