神宇股份：公司产品主要用于射频信号的接收和传输，不向终端客户直接供货

Group 1 - The company primarily engages in the research, development, production, and sales of RF coaxial cables, which are mainly used for receiving and transmitting RF signals [2] - The company's products are not supplied directly to end customers [2] - The inquiry about the company's involvement in brain-computer interface technology was addressed, confirming that it does not have related business [2]