Environmental protection engineering facility construction; Mechanical and electrical equipment facility construction; Metal wire rope and its product manufacturing and sales; Metal material manufacturing and sales; Traffic and public management metal sign manufacturing and sales; Production, sales, and installation of hardware, building materials, steel structures, sound barriers, protective fences, noise reduction barriers, mining screens, and metal materials; Sales of cement products, glass products, and plastic products; Research, development, production, processing, sales, installation, and service of machinery, electronics, and computer software and hardware products; Equipment repair, equipment anti-corrosion, equipment health management; Gas and liquid separation and purification equipment; Communication equipment; Instruments and meters; Generator sets; Battery power supplies; Wires and cables; Optical fiber and cable; Special vehicles (cooking vehicles, power vehicles, medical vehicles, repair vehicles, and other special vehicles) and shelters; Satellite transmission services; Information technology consulting services; Labor subcontracting (excluding labor dispatch); Import and export of goods and technologies.