Morphing Mugs Personalized Harry Potter Slytherin Robe Heat Reveal Ceramic Coffee Mug - 11 Ounces - ADD YOUR OWN NAME TO YOUR HOGWARTS HOUSE! Add your name(s) to this mug and reveal to the world which Hogwarts house you belong in! Color changing, add hot liquid and watch it change! Ceramic Mug, 11oz in size, weighs 1lb Officially licensed Harry Potter mug designed and printed in the USA by Trend Setters Ltd. Authentic Morphing Mugs(TM) brand heat-sensitive mug