Gaiam Kids Balance Ball Chair – Classic Children’s Stability Ball Chair, Alternative School Classroom Flexible Desk… $13.57 – $57.82 Make sure this fits by entering your model number. OFFICIAL KIDS CHAIR BALL: This 38cm Balance Ball is made exclusively for the Gaiam Kids Balance Ball Chair as an extra or replacement ball (Chair NOT included) ALTERNATIVE DESK CHAIR: The perfect kid-sized seat for improving concentration & focus at home or in the classroom at their desk, this exercise ball chair helps to reduce restlessness, fidgeting and prevent boredom