... flow, strong ventilation, low operating cost;2. Imported bearing, high-strength, low noise, durable3. Using air downstream principle, ... prevent backflow of air,4. High-strength more high-gluten strength aluminum-magnesium alloy wheel, light weight, high strength, toughness good5. 6 ... could satisfy varieties need of different customers.7. The high efficient and energy-saving motor passed the national 3C ...