•ISOAFS-PVC thermally insulated reinforced PVC flexible air ducts are specifically produced for low and medium pressure heating, cooling, ventilation, exhaust and air conditioning systems. •ISOAFS-PVC is highly resilient and can be used in applications with excessive vibration and/or perpetual motion systems. •Airtight ISOAFS-PVC is extremely durable, strengthened with high tension steel spring wire, surrounded with thick glass wool insulation and a PE vapour barrier. •ISOAFS-PVC is elastic and flexible. It can be easily fitted to circular, oval or rectangular connectors.