Keeping drinks hot and cold for everyday use. Stainless steel vacuum insulation virtually eliminates temperature change by creating an airless vacuum 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, or colder. It keeps liquid cold for 18 hours and keeps liquid hot for 8 hours. Whether you are heading to school or are just playing around the house, you will quickly find that this tumbler is the best choice for your little one.