Ampelair flexbile duct connector is formed through fold repression by using Ampelair fire-resisitant fabric and punching sheet. The gas tightness is good, the punching sheet is easy to be made into any shape ruquire, the installation is fast, it can replace the old common canvas to save time. As long as the galvanized sheet are bent into whatever shape that you need, you may use the tapping screw or the self-plugging rivet to tight them;Another method is to carries on spot welding processing. The result is that the stable,economical,effectiveflexibility connection can satisfy all matching requirement.