This Semi-Rigid Aluminum Duct is ideal for applications where code requires an all-aluminum product. This duct is totally non-combustible with a maximum operating temperature of 435°F and is UL2158A listed and marked. Approved for applications where the dryer manufacturer calls for a UL version of an all-aluminum product, as this UL duct is thicker than the standard version. New manufacturing technology incorporated into the duct allows for easy rotation and therefore more durable handling of the duct by the contractor or installer.