Advantages of Our Vacuum Flask We focus on the core function of Vacuum Flask - insulation. Our Vacuum Flask uses advanced vacuum insulation technology to effectively prevent heat transfer by forming a vacuum layer between the inner and outer layers of stainless steel. This means your hot drinks will stay hot for up to 24 hours, and your cold drinks will stay cold for up to 48 hours. Whether you're working outdoors, traveling or enjoying time at home, Vacuum Flask can provide you with long-lasting insulationWe paid a lot of attention to the material of Vacuum Flask. We have selected high-quality stainless steel materials to ensure Vacuum Flask has excellent corrosion resistance and wear resistance. https://www.qqjiali.com/product/vacuum-flask/