CB system (IEC system for qualification test and certification of electrical products) is an international system operated by IECEE. The certification bodies of IECEE member states test the safety performance of electrical products based on IEC standards, and the test results, namely CB test report and CB test certificate, are mutually recognized in IECEE member states. The purpose is to reduce international trade barriers arising from the need to meet the certification or approval criteria of different countries. IECEE is the abbreviation of the organization for qualification testing and certification of electrical products of the International Electrotechnical Commission.