The Mizuno RB Tour X golf balls are designed to provide high speeds and distances even on the windiest days thanks to the drag reducing C dimple. Additionally, 4-the Mizuno team has engineered a 4-piece cover made of high traction urethane for a soft and responsive feel. One of the defining characteristics of the Mizuno RB Tour X golf ball is the C Dimple. This is the result of 12 years of testing to bring you a golf ball that not only reduces drag but increase power of trajectory.