With a temperature gauge to let you know when your hot beverage is ready for that first sip, this heat sensitive Ceramic Fuel Gauge Mug (10 OZ) changes color based on the temperature of your drink. This fun and interactive ceramic mug features the sentiment OUT OF FUEL, a temperature dial design, and the ability to change from white to red depending on how hot or cold your beverage is. Comes packaged in a gift box. FDA approved. Ceramic.