Changsha Changsha County Hunan No.23 Concrete Machinery Machinery Manufacturing Machinery Engineering Construction Machinery Zhong Engineering Production Equipment Zhuan Yong Equipment Machinery Equipment Manufacturing Electromechanical Equipment Huan Bao / Energy Saving Metrology Equipment 高新技术企业 专精特新小巨人企业 科技型中小企业 省科技型中小企业 省级高新技术企业 国家专利