Chongqing Yuzheng Technology Co., Ltd. (hereinafter referred to as "Yizheng Technology") is a wholly-owned subsidiary of Yihong Technology. It was established in December 2017 and is a company specializing in the railway locomotive and rolling stock accessories industry. It focuses on urban railways, subways, and high-speed railways. R&D, design, production, independent inspection and service of carbon skateboards for motor vehicles. The developed carbon skateboard has passed the quality inspection of China Railway Research Institute and Harbin Electric Carbon Research Institute. The independently developed and produced carbon skateboard products have been used in the healthy operation of Chongqing Metro Line 1, Line 6 and Circle Line, and have been well received by customers. Chongqing Rail Group's 2018 Excellent Supplier. 镪正科技 has established a complete ISO three systems, and the outline of the production process is as follows: 1. Supplier management adopts the 5R principle and establishes a raw material inspection system. 2. In the production process inspection, the principles of self-inspection, mutual inspection and final inspection are adopted, and qualified products and unqualified products are separately stacked, and a warehouse of raw materials, semi-finished products, finished products, and unqualified products are established. 3. The establishment of the product factory inspection system, we carry out factory inspection according to the TB iron standard 2013 standard.