Dynamic inflatable double step can be used a non-rigid step for low-impact cardiovascular and aerobic activity and can be used in balance training and strengthening of the lower extremities * Inflate for your needs to your personalized comfort and exercise level * Made from soft, super strong, latex-free, BPA-free and phthalate-free vinyl * Ships uninflated and includes easy to follow exercise booklet * For ages 12 years and older - see product description for proper ball size guidelines