The waiters in Greek cafes are famous for their dexterity as they swing heavily loaded trays between tables with nary a spill. This sturdy device illustrates the principle in a way that will amaze your class. Place a clear container of colored water on the platform of the tray and start swinging from side to side. With practice, you should be able to swing in wide circles and even upside down. The container stays put because the net force acting on it is always directed radially, toward the center. This pins the container to the tray along with its contents. Our durable wood tray doubles as a laboratory support stand and can be clamped vertically or horizontally. It includes an attached pendulum and instructions. If you add magnets to the base (not included), you can also use the pendulum to demonstrate chaotic motion.