Roof Curb For Fan Base Size 64 in Curb Height 12 in Curb Inside Width 59 1/2 in Curb Outside Width 62 1/2 in Material Steel Standards UL 705 For Use With 64 in Square Base Adjustability Fixed Ventilation Type Nonventilated Application General Exhaust Curb Inside Length 59.5 Curb Outside Length 62 1/2 in Curb Shape Square Damper Tray Size 50 in x 50 in Features Flashing Flange One Welded Corner Wood Nailer Finish Galvanized Flashing Flange Width 2 in