Callaway big bertha fusion womens driverthe big bertha fusion driver is a material change in forgiveness and distance led by our revolutionary titanium exo cage and ultralight triaxial carbon crown with a new and innovative shape and industry leading aerodynamicsmaximum forgiveness from fusion technologybig bertha fusion pairs an aerospace grade titanium exo cage with our ultra light triaxial carbon crown and sole the fusion of these materials allowed callaway engineers to position substant