... outer diameter Silicone hot air duct for HVAC and ventilation systemMaterial: spring steel wire, glass fiber fabric, nylon line, ... meters Specification: 1.high temperature duct, as suction and blast hose, suitable for hot air , blower, exhausting gas, etc ... /5“255250412”3053004Application;cool and hor air transmission,air exhaust insrtuments. Silicone hot air duct for HVAC and ventilation system