The Travel tumbler is designed for those on the go. You can drink comfortably from any angle of the tumbler, like drinking from a glass. Designed to catch ice cubes if holding a cold drink, and when holding a hot drink, the double wall stainless steel vacuum insulation prevents heat transfer from the inner to outer layer. For maximum insulation efficiency, preheat or precool the tumbler prior to use by filling in a bit of hot/cold water for 1-2 mins.