Roof Curb For Fan Base Size 29 in Curb Height 12 in Curb Inside Width 24 1/2 in Curb Outside Width 27 1/2 in Material Steel Standards UL 705 For Use With 29 in Square Base Adjustability Fixed Ventilation Type Nonventilated Application General Exhaust Curb Inside Length 24.5 in Curb Outside Length 27 1/2 in Curb Shape Square Features Flashing Flange One Welded Corner Wood Nailer Finish Galvanized Flashing Flange Width 2 in