Party light cups made using food safe plastic, soft flexible plastic makes them extremely break and shatter resistant. Size: 16oz light up cups size is perfect for sodas, beers, juice, water, energy drinks, larger cocktails, root beer floats, ice cream, snacks, candy - and also great as a glow-in-the dark kids toy for stacking and building fun. Easy to use: Just turn on the switch of the LED light to enjoy the joy of this night.