CYG provides a full range of relay protection products covering from medium and low voltage to ultra-high voltage. Its core products include: the BP series busbar protection (such as BP-2C), applicable to all voltage levels and various main wiring configurations; the PRS series ultra-high voltage protection (such as PRS-753 line protection, PRS-778 main transformer protection), comprehensively applied in projects up to 1000 kV; and the PRS series protection and automation devices, flexibly used in various scenarios such as medium and low voltage feeder protection. Based on advanced principles such as complex ratio differential protection, these products feature high reliability, speed, and sensitivity. They fully support IEC 61850 standard communication and SV functions, meeting the requirements of digital substations, and comply with cybersecurity standards such as IEC 62443. The products have been widely applied in tens of thousands of substations worldwide, providing core assurance for the safe and stable operation of power grids.