Callaway's Extreme Notch Weighting is used in the design of the Big Bertha Irons clubheads. This redistributes the weight to the heel and the toe of the clubhead, low in the back. This is designed to give the club a high Moment of Inertia, which gives you better accuracy and distance on mishits.
Variable Face Thickness Technology also is used in the design of the club face. This lowers the center of gravity in the clubhead by varying the thickness of the face between .5 mm and 2.5 mm. In the lob wedge, this has the effect of providing height to its trajectory.
Big Bertha hosels are straight, hollow and short, which allows the weight to be distributed to the perimeter and lower on the club, where it is more useful. The hosels on the Big Bertha irons also are designed with Tru-Bore Technology. This is designed to allow the shaft to extend through the hosel and clubhead to the sole. By moving the end of the shaft closer to the middle of the club face, you should get improved feel and control.
The Big Bertha lob wedge has a loft of 60 degrees and a lie of 65. It also has a swing weight rating of D3 and a bounce angle of 9 degrees. Big Bertha lob wedges with senior flex--also known as an amateur or light flex--are available only with graphite shafts. They have a low kickpoint and a low to mid torque rating.