Empire Ventilator, Turbine, 4in - TV04G Price For: Each Bracing: External Bearing System: Features Oiless Bronze Upper Bearing and Lower Thrust Type ball bearing Requires: Base for New Installations Item: Turbine Ventilator Type: Wind Driven Throat Dia. (In.): 4 CFM @ 4 MPH Wind: 126 Overall Height (In.): 12 Overall Width (In.): 10-1/4 Construction Material: Galvanized steel With Aluminum Bracing Includes: - Country of Origin (subject to change): United States