The outdoor vacuum flask is also called an outdoor thermal water kettle. Its appearance is similar to a large stainless steel insulated water bottle. Usually, the outdoor vacuum water flask capacity will be larger than 1000ml, and the most popular is the capacity above 2.5L. It will come with a portable handle and multifunctional lid for easy carrying and drinking of hot water outdoors. The outdoor vacuum flask's biggest feature is that it can keep the temperature of hot water for a long time without major changes. Great for hydration in cold weather and outdoors. If you are outdoors in summer, it can also maintain the cool taste of ice water, allowing you to enjoy the stimulating experience of ice water in a hot environment.