General project: Sales of metal products; Manufacturing and processing of doors and windows; Construction of metal doors and windows engineering; Manufacturing of metal structures; Manufacturing of metal chains and other metal products; Sales of metal chains and other metal products; Manufacturing of metal materials; Sales of metal materials; Research and development of metal products; Sales of metal structures; Sales of doors and windows; Internet sales (except for the sale of goods that need to be licensed); Import and export of goods; Technology import and export. (Except for projects that require approval according to law, conduct business activities independently based on the business license in accordance with the law)