An exercise ball, also known as a yoga ball, is a ball constructed of soft elastic with a diameter of approximately 35 to 85 centimeters (14 to 34 inches) and filled with air. The air pressure is changed by removing a vale stem and either filling with air or letting the ball deflate. It is most often used in physical therapy,athletic training and exercise. Product information TypeYoga ball MaterialECO-friendly PVC OEMYES ColorCustomized LogoCustomized Size45/55/65/75cm or customized FeatureAnti-burst and durable PackingBag and carton ApplicationHome use/commercial use,fitness training weight lifting Product Details It can also be used for weight training. The ball, while often referred to as a Swiss ball, is also known by a number of different names, including balance ball, birth ball, body ball, ball, fitness ball, gym ball, gymnastic ball, physio ball, pilates ball, naval mine, Pezzi ball, stability ball, Swedish ball, or therapy ball.Wholesale Exercise Ball website:http://www.chinaphoenixfitness.com/yoga/exercise-ball/