Develop strength, increase your flexibility, and improve coordination with the ExerFlex fitness ball. Perfect for fitness, rehabilitation, or just for fun, the ExerFlex fitness ball provides several activities and exercises designed to strengthen all the major muscle groups for a total-body workout. Reduce low back pain and alleviate stress with specific exercises. Develop a fine-toning routine to help you shape and sculpt your body with the ExerFlex workout DVD. An air pump is included for your convenience. The ball can also be adjusted in size from 50cm to 65cm.