国缆检测：公司主营业务为电线电缆及光纤光缆的检验检测等专业技术服务

Group 1 - The company, Guolan Testing (301289), specializes in inspection and testing services for wires, cables, and optical fibers [1] - The company has developed capabilities for testing and evaluating aerospace cables, focusing on quality and technical requirements for major engineering and equipment supporting cables [1]