When the mug is cool, it is ringed with five becoming young ladies, each in her walking attire and bonnet. When the mug is warm, the young ladies change into lovely evening attire. • All of our disappearing mugs come in a beautifully designed, colorful box. • Heat activated color changing mugs are microwave safe, but not dishwasher safe. Hand wash only. Don't soak. • UPG is a novelty gift company specializing in smart and funny gifts. Check out our shop for all types of quirky fun stuff!