Second, the face on the XR is 10 percent lighter, and the center of gravity (CG) is 17 percent lower than last year's X2 Hot. Similar to this fall's Big Bertha Alpha 815 drivers, it utilizes a ...

New on the market: Callaway XR 16 Sub Zero Driver. The scoop: The XR 16 Sub Zero represents the lowest center of gravity Callaway has ever engineered in a driver.