€¢ This duct is ideal for applications where code requires an all aluminum duct €¢ Totally non combustible with a maximum operating temperature of 435 deg F €¢ The continuous lock seam permits the duct to be pulled open; compressed; bent and re-bent without developing leakage The 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 deg F."