A Character-based Vacuum insulation. It is a big deal if you care about beverage temperature change. Double-wall construction means that hot liquids can remain hot for up to 12 hours while colder choices can last a full 48 hours; that’s two whole days. Furthermore, these bottles are condensation-proof - no sweating or slipping. Built to fit standard vehicle cup holders, the stainless steel sides are both scratch and fade-resistant.