As our main product of a rectangular galvanized duct, it is completed mechanically through all automated processes. And it has better shape than the existing manually-manufactured product and is completely airtight. It can be manufactured as a P. V. C. duct, a color duct and a SUS duct as well as a galvanized duct type. And recently a galavalume duct has been increased, which is more durable than a GI(galvanized)...