The Lambro 4 In. x 8 Ft. flexible white vinyl duct is ideal for bath fan exhaust and other general venting applications that require moist air and humidity from exiting the home. This duct is made from vinyl (PVC) material bonded with an adhesive with a maximum operating temperature of 158F. This duct is not recommended for higher temperature applications. The duct is supported by a steel wire helix spiral frame to prevent collapsing. Check local building codes prior to installation.