星帅尔：公司主营业务为研发、生产和销售制冷压缩机用热保护器等

Group 1 - The company, Xing Shuai Er, focuses on the research, production, and sales of various products including thermal protectors for refrigeration compressors, starters, sealed terminal blocks, optical communication components, optical sensor components, temperature controllers for small appliances, and small to micro motor products, as well as solar photovoltaic components [2]