It's Heat Sensitive mug. It will change it's color and the design will be visible as soon as you pour in any kind of hot beverage & It will turn black as it cools down.
(1)Due to various types of computers ., the actual color of the item may be a little different from the picture.
(2)Avoid Microwave and dishwasher safe, Wash with hand Only
(3) do not put it under sun for a long time
(3)Size: about Wide 8.2cm，Heigh 9.6cm