Quick Wristband Maker

  A device that stretches out those things below the cap on a plastic bottle and turns them into a wristband. It could be done by mounting on 2 wheels that spin it fast and slide apart from each other to get even stretchage.
  There are ways of making them out of the thin plastic thing inside the cap, but if you haven't practiced a lot, it results in failure. This would be a fail-safe wristband maker