Gold"s Gym Fitness Ball, 55cm: Exercise ball will help you get fit and stay strong by: * Targeting abdominals and lower back to strengthen the core * Creating a stronger, more balanced upper body * Working your arms, chest and shoulders. * Delivering a low impact workout * Perfect for any fitness level Gold"s Gym Workout Equipment Kit includes: * 55cm Exercise Ball * Air Pump * Workout guide * Ideal for users 5 ft. 3 in. and under