Roof Curb For Fan Base Size 34 in Curb Height 12 in Curb Inside Width 29 1/2 in Curb Outside Width 32 1/2 in Material Steel Standards UL 705 For Use With 34 in Square Base Adjustability Fixed Ventilation Type Nonventilated Application General Exhaust Curb Inside Length 29.5 Curb Outside Length 32 1/2 in Curb Shape Square Damper Tray Size 27 in x 27 in Features Flashing Flange One Welded Corner Wood Nailer Finish Galvanized Flashing Flange Width 2 in