The callaway great big bertha driver leave no yard behind its designed to get the most distance for all categories of golfer this callaway golf driver is a technological breakthrough that includes a multi material aerodynamic shape and a sliding weight so that you leave no yard behindto get every last yard out of your driver you need more speed thatrsquos why callaway golf put in their next gen rbullmoto technology it provides the structure for a thinner face leading to h