Balego Heavy-Duty Exercise Fitness Balance Ball, 65 cm (25") Green 45 cm Burst Resistant Fitness Ball  Orange Burst Resistant Fitness Balls are specially formulated to resist rapid deflation if punctured. (Maximum safe load: 600 lbs.) Improves gross motor control, balance, range of motion, equilibrium, and more. Under general guidelines, this ball is good for people who are 5 5" to 5 11" in height but this can vary depending on exercises, use, torso length and/or other factors. Please consult your therapist, physician, or personal trainer to determine the best size.