Stiff Flex The legendary Great Big Bertha returns as Callaways most technologically advanced driver featuring an ultralightweight chassis and easytoswing design This new driver is almost 30g lighter than a tour driver with unmatched distance and club head speed The Forged Carbon Sole and Triaxial Carbon Crown greatly enhance MOI allowing Callaways engineers to move the CG from the weight savings lower and deeper increasing forgiveness Jailbreak AI Speed Frame is designed for horizontal and torsional stability to promote higher ball speeds across the face The AI Flash Face cup now includes spin optimization and increased speed and distance Great Big Bertha returns with a material difference in performance GlobalGolfcom online store offers superior selection service and quality for your Callaway golf Clubs needs