Was given to me as a gift, but never used it! About this item (Amazon Description) Ember Coffee Mug with Longer Lasting Battery: Our updated smart coffee mug's extended battery life keeps your drink at your preferred temperature (between 120°F - 145°F) for up to 80 minutes on a full charge or all day on its redesigned charging coaster Smart With or Without App: Pair this temperature control mug with the Ember app to set the temperature, customize presets and more; Our self-heating coffee mug is also functional without the app and remembers your last-used temperature (135°F out of box) Auto Sleep: Our heated coffee mug intelligently senses when to turn on and off; The mug enters sleep mode when empty or after 2 hours of inactivity; Ember wakes up when it senses movement or liquid Hand Wash Only: An updated scratch-resistant coating is safe to hand wash; Ember Mug 2 is IPX7 rated and fully submersible up to 1 meter deep Perfect Gift for a Life Well Sipped: Whether self-gifted or given to another, there's no better way to share warmth than a favorite drink at just the right temperature every time