Using the force of gravity going down due to the weight of the weights, the Da vinci rolling ball timer moves the table through which the beads pass like as a seesaw. Every time the iron ball comes down from top to bottom, it moves down the table one by one and changes the position of the table. Measures the amount of time it takes for the ball to move left, right, up and down, and tells you the time. Ages 8 years and above.