Manufacturing and sales of railway train HVAC equipment and train interior metal decorative panels; manufacturing and sales of railway train refrigeration, air conditioning, and ventilation equipment; precision sheet metal processing for train air conditioners; maintenance and servicing of rail vehicle and locomotive air conditioners; manufacturing and sales of chemical fiber machinery and parts, textile machinery, electric heaters, and ship machinery parts; surface treatment of metal materials (excluding electroplating); sales of ship outfitting parts; construction of ship outfitting projects; self-operated and agency import and export of various goods and technologies (excluding those restricted or prohibited by the state). General items: spray coating processing; processing of mechanical parts and components.