Callaway Big Bertha X-12 Irons feature a low center of gravity to help get the ball airborne. The Callaway Big Bertha irons include a variable 36-degree undercut channel that creates a thinner profile and gives optimal weighting for less drag and improved performance out of the rough, plus a larger effective hitting area. The Big Bertha X-12 Irons also incorporate S2H2 and Tru-Bore technologies for forgiveness and feel.