Pound the ball into the opening at the top of the stair and see it drop to the next level waiting to be pounded again. This set includes a solid wood ball and mallet, and a three-level stair with an opening on each step. The opening has a silicone ring set in it to keep the ball from dropping through until it is pounded a few times with the mallet. This activity helps to develop gross motor skills, hand-eye coordination, and encourages observation of cause-and-effect. The stair stands 21 cm tall (about 8.5").