When it's cold, the mug is encircled with elegant silhouettes of birds on a wire. Pour in a hot beverage and watch as 18 bird species appear in full color. Go ahead and tweet about it! Perfect for any hot beverage: coffee, tea, hot chocolate, pumpkin spiced beverage. • 10 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!