The CB system is the first truly international system of mutual recognition of electrical product safety test reports. Multilateral agreements between national certification bodies (NCBs) in various countries allow manufacturers to gain the national certification of other CB member countries by virtue of a CB test certificate issued by the NCB. The CB system is based on international IEC standards. If the national standards of some member states are not yet fully consistent with the IEC standards and allow the existence of national differences, they should be made public to other members. The CB system uses the CB test certificate to confirm that the product sample has successfully passed the appropriate tests and meets the relevant IEC requirements and the requirements of the Member State concerned. The main goal of the CB system is to promote international trade by bringing manufacturers closer to the ideal goal of "one test, multiple uses" by promoting the harmonization of national and international standards and the cooperation of product certification bodies. The current electromagnetic compatibility (EMC) is not included in the CB system.