Bertha's back, and she's meaner than ever! The new Callaway Lady Big Bertha Driver is so revolutionary, it deserves to carry one of the most legendary names in golf. It's faster and more robust and features Callaway's new Adjustable Perimeter Weighting for maximum distance via total driver performance. Hyper Speed Face: The new Hyper Speed face design is nothing short of groundbreaking - it's lighter (10% lighter), hotter, and more robust than ever before, increasing ball speeds on shots hit across the face Callaway's longest Total Performance Driver Adjustable Perimeter Weighting: Callaway put their new Adjustable Perimeter Weighting slide toward the rear of the club, which leads to significantly higher moment of inertia (MOI) and forgiveness, while offering a wider range of draw and fade bias options. All that amounts to longer, straighter shots 20% higher MOI than Razr Fit Extreme Advanced Adjustable Hosel: Increase or decrease loft in 1° increments (up to +2&d