FitBALL Mini Exercise Ball (9 inch) Lengthen from head to toe. Perfect for enhancing core muscle activation, body rolling techniques and postural re-setting activities. Improves balance, posture, core strength and overall stability. A Must-Have Fitness Prop. Our exercise ball is designed to be universally helpful. Thats why it can be used in conjunction with Yoga, Pilates, Crossfit or other training routines. Physical Therapist Recommended. Part of getting healthy is regaining lost strength due to pregnancy, injury or sickness. Our Pilates ball allows you to improve muscle groups and balance with a low impact support. Soft, light and burst resistant ball, allows to perform a wide range of exercises that vary from muscle strengthening to low-impact exercises. Anti-burst balls do not include a valve, but rather have a plug to withstand high pressure. This requires a straw for inflation. Straw & Plug kit included.