Great Big Bertha
C
ompared to the Big Bertha War Bird (Stainless Steel) Driver, the Great Big Bertha Driver is a full 25% larger, with a one-inch-longer shaft. There are two main benefits to the design. First, the enlarged hitting area gives players of every skill level greater confidence. Second, the increased length enables players to achieve increased clubhead speed without swinging harder.
The company:
http://www.callawaygolf.com