meets the requirements of the 1974 International Convention for the Safety of Life at Sea, the MSC218 (82) and MSC.48 (66) International Lifesaving Equipment Code, the MSC.81 (70) Revised Lifesaving Equipment Test Recommendations, and relevant amendments. This product has two independent air chambers, each tightly connected to an automatic inflation system and a manual inflation system. In the event that any one air chamber loses buoyancy, the other air chamber can be manually activated, still meeting the use requirements. It has a dual safety effect, and can also be used simultaneously with both air chambers. This product is small in size, light in weight, comfortable to wear, and convenient to use. It can automatically expand within 5 seconds after entering the water. It is an emergency rescue equipment for passengers on board, and is also suitable for lifesaving of various types of water navigation ship operators. The products have also been approved by China Classification Society (CCS) and the Fishery Vessel Inspection Bureau of the People's Republic of China.