Tunnel Ventilation Fan Blade Material: Cast Alloy aluminum Diameter: 250-2250mm Blade, Axial Fan, Fan, Ventilator, Air-condition, Centrifugal fan, Ventilation, Ventilating Fan, Blower, Industrial Fan, Ventilation, Ventilator Fan, Ventilation, Ventilator Fan, Air Mover, Air Moving Features:1) Application: all kinds of centrifugal fans2) Diameter from 250mm to 2,250mm.