This large balance board provides room for two to stand on it and work as a team to rotate the ball along the pattern. Use the two interchangeable disks to add variety. Another idea - pick up the disks and use them as a tool to work on hand-eye coordination. Each board includes three balls. The 18-7/8" dia. balance board pattern is a fish and the two disks (11-5/8" dia.) are 2-D and 3-D yin-yang symbols. Age 3 and up.