When purchasing a thermos cup, you must choose a food-grade stainless steel liner, which is suitable for heat preservation and cold preservation, relatively resistant to falling, safe and convenient for daily use, but not suitable for making tea and coffee. It is recommended to buy a thermos cup with an antibacterial stainless steel liner. Cu+ antibacterial ions are added to food-grade stainless steel, which not only has antibacterial properties, but also has better corrosion resistance, and can be used for healthy drinking in daily life. For details, please refer to Japan's first antibacterial thermos cup. This information is available on Baidu.