The VR Pro Combo CB Irons have key performance features for the right club and right distance. These have more grooves that are closer together and deeper to help ensure maximum flight control and shot-to-shot consistency. Moreover, these Nike CB irons conform to the new USGA and R&A rules. Through Linear CG (center of gravity) Mapping, the CG moves gradually and consistently throughout each club in the set for optimal launch and consistent distance control. The precision-forging to a near-finished level eliminates most hand work and ensures consistency throughout the iron set. The iron face is finished and milled to a perfectly flat surface then carefully die-stamped, pressing grooves to exact specifications for extremely low variance and shot-making consistency. So, you can enjoy more control!