Non-insulated aluminium flexible air ducts are specifically designed for low- and medium-pressure applications in heating, cooling, ventilation, exhaust, and air conditioning systems. The airtight hose is manufactured from multi-layer aluminium and polyester, reinforced with high-tension, hard steel spring wire. Its fire resistance has been tested and certified by various international bodies. In the event of fire, the hose does not release any toxic or poisonous gases