AW Green 23.2″/59cm Yoga Balance Ball w/ 2 Elastic Strings Fitness Strength Exercise Half Ball Balance Trainer $49.99 – $57.90 Make sure this fits by entering your model number. [Multifunctional Balance Trainer]: You can strengthen your muscles and practice your body flexibility, which increases core strength, improves body balance, stability, coordination, endurance, flexibility etc. [Anti-Slip Design]: The exercise ball base is equipped with 8 anti-slip rubber feet, which can improve users’ stability to a maximum extent. Maximum user weight: 440 lbs