... radius is same as outer diameter Silicone hot air duct for HVAC and ventilation systemMaterial: spring steel wire, glass fiber ... and blast hose, especially suitable: -For transmission hot and cold air. -For printing machines, blowers and compressors. -For exhausting gas, engine construction, engine ... โ20520049 4/5โ255250412โ3053004Application;cool and hor air transmission,air exhaust insrtuments.