When the mug is cold, the Bat-signal lights up the sky. Looks like there's trouble in Gotham City! When the mug is hot, the Caped Crusader appears to save the day!
Of course, sometimes the Bat-signal only means the Commissioner has just put the kettle on...
Holds 14 oz / 400mL.
Disappearing mugs are not dishwasher safe but are microwave safe.