et this portable stainless steel thermos flask to keep hot things hot and cold things cold with this heavy duty vacuum thermos. Unbreakable stainless steel thermos maintains temperature for several hours. Great for work, school, travel, camping, sports, and more thermos vacuum insulation technology virtually eliminates temperature change within the beverage container by creating an airless space between two stainless steel walls. The result is an insulation layer that performs better than any other. A superior insulated container you can depend on to keep your beverages hotter, colder, fresher, longer.