Research and development of mechanical equipment; production and sales of pneumatic power machinery and components, fasteners, valves and plugs, automobile and motorcycle accessories, industrial automatic control system devices, railway locomotive accessories; sales of new energy vehicle electrical accessories; battery sales; sales of mechanical equipment; sales of hydraulic power machinery and components; sales of rail transit special equipment, key systems and components; sales of electronic components and electromechanical component equipment; sales of forgings and powder metallurgy products; non-residential real estate leasing; import and export of goods; import and export of technology. .