Use this stadium cup to hold an ice cold and hot drink, and watch as it changes from one bold, vivid color to another in seconds as the color change plastic reacts to the difference in temperature.Made of PP, the tumbler is BPA free and is conveniently top shelf dishwasher safe,Reacting to ice cold liquids, the cup changes from one vivid color to another as the temperature drops,yellow turns green, the blue color turns purple,etc.