Air Vent 5005664 21.3 x 14 in. Dia. Air Hawk Mill Aluminum Turbine & Base
3 in.Maintenance free top and bottom dual bearing systemTurbine head and base designAluminum constructionPart of a balanced attic ventilation system for year round airflowHelps to fight heat and moisture buildup inside an attic as well as ice dams in cold climatesRequires intake ventilation for proper performanceSpecificationsSize: 21.Country of Origin: United StatesWeight: 6.