神宇股份：公司主要从事射频同轴电缆的研发、生产和销售

Group 1 - The company, Shenyu Co., Ltd., primarily engages in the research, development, production, and sales of RF coaxial cables [2] - The products of the company are mainly used for the reception and transmission of RF signals [2] - The company does not supply products directly to end customers [2]