Thermos brand products offer superior cold retention that keeps beverages cool and delicious for hours, and the Thermos 2465TRI6 Vacuum Insulated 18 Oz. Stainless Steel Hydration Bottle is no exception. 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 colder, fresher, longer. This hydration bottle keeps beverages cold up to 12 hours more than 10 times longer than an ordinary plastic water bottle.