Stainless steel vacuum insulation keeps beverages hot or cold for hours; Heat retention: 189°F @ 1 hr. / 160°F @ 6 hrs. ; Cold Retention: 46°F @ 6 hrs. 2-step lid release process prevents excess condensation on the stopper from being flung off while the lid opens Air vent on the mouthpiece allows beverages to flow out smoothly, without gushing or overflowing Stopper disassembles for thorough cleaning and tight fitted flip-open lid keeps beverages hotter or colder Easy-to-clean nonstick coated interior