Weproducemanykindsofroofturbineairventilators,suchasTG-880,TG-600.TG-500,TG-300.TG-880arespeciallyusedinthemachineryfactory,paperfactory,storerooms,andthebigbuildingswhichhavemuchharmfulairandthetemperatureisveryhigh;TG-600.TG-500areusedinthegeneralindustriesroomsandthesmallbuildings;TG-300areusedintheadvancedhousesandtheventilatingpipes. Advantages: ØItisnoelectricityorenergycostingandnoiseless,exhaustingairnaturallyandeffectively.Itcanworkforalongtimesoastomakefreshaircirculating. ØGoodsurfaceself-lubricatingperformance,superioranti-corrosion,weatherresistance,strongwearresistance,longservicelife,lightweightandhighsensitivity. ØMinimumpackingmeasurement.Easytoinstall. Ø15yearswarranty. 1.Theballdiameteris420mmandthethroatdiameteris300mm. 2.TheyaremadeofstainlesssteelandtheUBCbearingsweusearefromtheUSA. 3.Weguaranteetheusageofourturbineventilatorsfor15years. 4.Wecandesignothersizesaccordingtoyourdemands. 5.TheyaremainlyusedontheResidentialbuildings,villasandthefluestoventilateandchangetheair