The Large 60 cm Balance Fit Disc can withstand up to 450 lbs. It promotes core stability and has many of the same benefits of a gym ball while performing lower back and abdominal exercises. Can be use in most chairs too: Support and challenge the spinal muscles while enhancing posture. For children with hyperactive nervous systems - enhances calmness and concentration. Can be used on the floor for exercises to: Improve balance and increase strength. Inflatable with a standard ball needle and pump (not included).