Workouts using the Mini Stability Ball will help to improve posture, balance, strength and flexibility with a major focus on lengthening and strengthening muscles. This ball is also a great tool for yoga and pilates. Children also love this soft ball. It inflates easily with a straw (supplied) to a diameter depending on the desired firmness and deflates very quickly for easy storage. The ball is responsive to the touch and non-slip when placed against a hard surface.