Thanks to the unique Vacuum Isolated Copper Coating technology, FLSK thermos bottles keep your beverages cold for up to 24 hours and hot for up to 18 hours. There is a vacuum layer between the stainless steel, which prevents heat or cold from escaping, since unlike air, it does not conduct heat or cold. In addition, an additional coating of the stainless steel with copper ensures that the temperature is maintained. The perfect temperature - always and everywhere. The insulated bottle combines high technical requirements with perfect design, which makes it a very functional and visually appealing drink bottle. The FLSK thermos flask is light, handy and available in three different sizes. The lid is completely sealed - every leak is a thing of the past. In addition, the insulated bottle is carbonated, tasteless, completely BPA-free and ecologically sustainable. The high-quality workmanship of the stainless and tasteless type 304 stainless steel ensures that your new FLSK will become a long-standing, reliable companion you won't want to miss.