This insulated flexible duct is made of thickened aluminum foil combined with a high-strength elastic spiral steel wire, providing a structure that is both flexible and durable. The middle layer features glass fiber insulation, which offers resistance to high temperatures, acids, alkalis, and flame spread. The glass wool insulation used in this duct has an R-value of R-4.2, contributing to thermal efficiency and helping to minimize heat gain or loss in ventilation systems. This insulation material also exhibits good corrosion resistance. Its operational temperature range extends from -4°C to 454°C, making it suitable for a variety of environmental conditions. The internal structure of the glass wool is fluffy yet has a relatively high density, allowing it to absorb sound waves effectively. In many setups, noise transmission can be reduced by up to 85 percent, which can be beneficial in spaces where quieter operation is desired. One notable feature of this flexible duct is its ability to bend without requiring rigid elbows. This flexibility simplifies installation in tight or irregular spaces and reduces the number of connection points needed. The aluminum foil jacket is self-sustaining, meaning it does not retract or collapse after being extended to the desired length. Color: Silver.