This fashionable, fabulous Penguin Party heat-transforming mug arrives in its own gift box and ready to party. When the mug is COLD, the penguins sport black-and-white formalwear for after six. When the mug is HOT, the penguins wear their most festive attire... the party's just getting started. • 12 oz. Ceramic coffee cup with a comfortable handle. • 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!