Built-In Rechargeable Battery – 3 Hour Battery Life Temperature Range – 120°F - 145°F Touch Display – Increase or decrease your temperature directly from the mug Safe to hand wash – Fully submersible up to 1 meter deep. Leak-proof Lid – keeps your beverage from spilling Description Designed to be used on-the-go, the Ember Travel Mug² does more than simply keep your coffee hot. Our smart heated travel mug allows you to set an exact drinking temperature and keeps it there for up to 3 hours, so your coffee is never too hot, or too cold.