This exciting new ceramic coffee mug changes color when a hot beverage is added. This mug makes drinking tea, coffee, hot chocolate or soup a whole new experience! A truly unique mug. When it’s cold, it’s just a simple black mug. When you add any hot beverage (water, tea, coffee, etc.), your mug turns white and the Cummins Fleetguard image comes to life in vibrant colors. 11 oz.