The registered address of tianjin is 200 metres north of yang jin zhen zhang village, yang jin zhang township, tianjin district, tianjin city, and the registration authority is yang zheng zheng zhang market supervision authority, represented by a legal person, wang zyu zhong, who operates on general projects such as: construction of metal structures; manufacture of light-quality construction materials; sale of light construction materials; sale of metal structures; sale of construction materials; sale of heating materials; sale of mechanical equipment; sale of construction decoration materials; retail sale of hardware products; construction of metal doors and windows; sale of metal products. (in addition to projects subject to authorization under the law, activities are carried out autonomously on the basis of a licence). Licensed projects: professional construction work. (a project subject to approval by law may be carried out only with the approval of the relevant department, depending on the document or licence approved by the relevant department)。