Manufacturer Says:

The best combination of feel and distance in a 2-piece ball we could make.
Quite simply, the results surprised even us. A golf ball this soft, and with this much feel, shouldn’t be able to go this far. The new Big Bertha Diablo provides the best combination of distance and feel we could generate in a 2-piece golf ball. The new advanced High-Resiliency Core is soft for stealthy feel while also providing wicked distance. The soft ionomer cover with HEX Aerodynamics adds to the feel while also providing longer, more penetrating ball flight for added distance.

Where to get it: Callaway Big Bertha Diablo 2009 Golf Balls