Color changing mug 1.Can change color when meet hot water. 2.Can pass FDA & SGS 3.Dishwasher-proof 4.OEM ... mug surface works just like a magic when you pour hot water into the mug,you can see a handsome men without ... 7-8 working daysUsage coffee mug, tea mug, milk mug, water cup, gift mug, advertising mug,promotional mug, beer mug, office ...