When you pour in hot liquid, the mug shows what will happen when the polar ice caps melt before your very eyes. Coastlines shrink and ocean levels rise, Florida dissolves and Central America all but vanishes. • 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!