Research and development of metal products; research and development of hardware products; manufacture of photovoltaic equipment and components; sales of photovoltaic equipment and components; manufacture of metal structures; sales of metal structures; manufacture of hardware products; wholesale of hardware products; retail of hardware products; metal cutting processing services; processing of mechanical parts and components; sales of mechanical parts and components; manufacture of doors and windows; sales of doors and windows; sales of power electronic components; sales of metal materials; sales of rubber products; sales of plastic products; sales of textiles and raw materials; sales of sealing parts; manufacture of metal daily necessities; sales of metal products; manufacture of auto parts and accessories; wholesale of auto parts; retail of auto parts; manufacture of high-speed rail equipment and accessories; sales of high-speed rail equipment and accessories; manufacture of railway locomotive and rolling stock parts; sales of railway locomotive and rolling stock parts; technical services, technology development, technology consulting, technology exchange, technology transfer, technology promotion; internet sales (excluding goods requiring sales permits); import and export of goods; import and export of technology.