Production and sales of rubber bearings, pot bearings, expansion joints, waterstops, embedded parts at beam bottom, drain pipes, guardrail supports, waterproof materials, geotechnical materials, anchorage devices, corrugated pipes, sealants, foam plates, double expansion rings, pipe plugs; Installation and maintenance of bridge bearings, expansion joints, waterstops, embedded parts at the bottom of beams, drainage pipes, guardrail supports, rubber fenders, rubber airbags, waterproof materials, geotechnical materials, anchorages, and corrugated pipes; Road and bridge maintenance engineering, bridge deck, tunnel waterproofing engineering construction; Import and export of goods (excluding goods prohibited by the state or involving administrative approval). (For projects that require approval by law, business activities can only be carried out after approval by relevant departments)