Turbine Ventilator Throat Dia 14 in 700 cfm CFM @ 4 MPH Wind Overall Height - Roof Ventilators 19 3/4 in Overall Width - Roof Ventilators 22 3/4 in Bracing - Roof Ventilators External Construction Material Galvanized Steel With Aluminum Bracing Oiless Bronze Upper Bearing and Lower Thrust Type Ball Bearing Requires Base for New Installations Flashing Includes -