Funky Heat Sensitive Color Changing ON/ OFF Switch High-Grade Porcelain Fashion Coffee Mug/ Cup(Black)

1) When pour the hot water into the cup, the cup’s outer wall will gradually chang from black to white, while black hidden, it will show up “ON” in front of you, OFF will disappear

2) When the mug cooled slowly, it will gradually change back to black, ON disappear again, OFF reappear

3) Material: High-Grade Porcelain

4) Height: 9.1cm

5) Diameter:

-Outer: 77 mm

-Inner: 70 mm