Designed for home or office, the new Ember Mug² does more than simply keep your coffee hot. It allows you to set an exact drinking temperature, so your coffee is never too hot, or too cold. Smart LED indicates when beverage has reached its perfect temperature and more. Select your temperature range as 120°F - 145°F (50°C - 62.5 °C) on the mug or with the Ember app. Built-in Auto-Sleep function intelligently senses when to turn on and off. Ember then maintains your chosen temperature for up to 1.5 hours with the Ember Mug² when off the charging coaster. If you are keeping your beverage hot while using the coaster, it can maintain your perfect temperature all day! Ember Mug² is safe to hand wash and submersible up to 1 meter in water. Compatible for Apple devices operating system: iOS 12.0 and above and Android devices operating system: 8 and above. Once your Ember Mug has an empty battery, place the mug on the charging coaster for approximately 2 hours for a full charge.