First, the cross axial flow impeller materials: steel, aluminum, stainless steel, ABS, glass fiber reinforced plastic impeller diameter: ￠ 200 ~ 2400mm Application: building wall and roof fans with; transformers, chillers, cooling towers and other equipment; cooling fans available. Second, the hub axle, mixed (oblique) flow impeller materials: steel, aluminum, stainless steel, glass and steel impeller diameter: ￠ 150 ~ ￠ 1500mm Applications: Building fire smoke, pipe axial, mixed flow, oblique flow fan ventilation sent use and so on. Third, the centrifugal impeller material: steel, galvanized steel, aluminum, stainless steel, glass and steel impeller diameter: ￠ 150 ~ 1200mm Application: building supply and exhaust fan use. Purification unit is equipped with air-conditioning equipment. Four fiberglass hood, impellers, duct, spiral, elbow, collector and other corrosion occasions optional