Show your love of the Harry Potter book series with this heat-sensitive color-changing ceramic mug. This beautiful collectible features the official book cover art of Harry Potter and the Chamber of Secrets. Watch as the exterior of this 11-ounce Harry Potter The Chamber of Secrets Morphing Mug magically transforms from black as hot liquid is added, revealing the hidden image in full vivid colors! Do not microwave. Hand wash only. Not dishwasher safe.