Designed for home or office, the Ember Mug 2 does more than simply keep your coffee hot. Our smart mug allows you to set an exact drinking temperature, so your coffee is never too hot, or too cold. Ember then maintains your chosen temperature for up to 1.5 hours with the Ember Mug 2, 10 oz and up to 80 minutes with the Ember Mug 2, 14 oz - so your hot beverage stays perfect. Ember Mug 2 is safe to hand wash and submersible up to 1 meter in water. Smart LED Indicates when beverage has reached its perfect temperature and more. Built-In Battery 10 oz - 1.5 hours 14 oz - 80 mins All day when placed on charging coaster. Auto Sleep Intelligently senses when to turn on and off. Temperature Range 120°F - 145°F (50°C - 62.5 °C). Select your temperature with the Ember app. Item appears to work as intended. Please understand you are buying a product that was used and then stored for an extended period of time. Seller makes no guarantees or warranties about the electronic components of this item.