Roof turbine Ventilators 1.High resistant to corrosion 2.Long life and high tensile,easy 3.No ... nosie,no energy cost. Roof turbine Ventilatorsbine Ventilatorsadvantage:high resistant to corrosion,long life and high tensile,easy installation,no nosie ... operations, and effective operations.2, the central axis with fine steps, to make the turbine blades under high speed and never deformed ...