The Valeo 75-centimeter body ball helps improve your core strength flexibility balance coordination and muscle tone making it an ideal addition to your exercise routine. Sitting on the body ball forces your body to stay balanced thereby strengthening your stabilizing muscles and core. You can design an extremely effective workout routine using the ball as a bench for dumbbell flies shoulder presses or ab crunches. The 75 cm body ball is designed for people who stand between 6' 1" and 6' 9". Valeo also makes 55 cm and 65 cm sizes.