Turbine roof ventilators eliminate electrical operating costs and offer low maintenance and quiet operation. Turbine ventilators are lightweight compared to standard ventilation units; providing easy installation without structural modifications. Roof ventilators are made using corrosion resistant aluminum with high quality bearing and shaft assembly. Withstands extreme weather and winds up to 123 MPH, and prevents water penetration. Wind driven turbine ventilator utilizes vertical vanes that rotate when wind flows through to exhaust air. Included flashing base eases installation. Available with Straight Flue for flat roof surfaces or Vari-Pitch Flue to fit virtually any roof pitch. Purchase Optional Dampers & Shutters to adjust airflow or seal-off exhaust vent when not in use. 15 Year Limited Warranty.