Callaway Big Bertha B21 Golf Irons – SteelThe Callaway Big Bertha B21 Golf Irons in Steel aims to provide you with distance. The legendary Big Bertha shape now involves a new formula which when present, enables more distance and increased forgiveness. Callaway’s Big Bertha B21 Golf Irons offer high ball speeds and increased spin robustness from an industry-leading A.I Flash Face Cup plus, further enhanced with 360 Face Cup which flexes and releases at impact. An improved turf interaction can be noticed as the Callaway Big Bertha B21 Golf Irons have a club profile that makes use of better shaping. And while you can achieve higher launch conditions, Callaway has also added a significant amount of tungsten weighting which deepens CG to achieve extraordinary precision. Features & BenefitsFast Ball Speeds From The First A.I. Designed Big Bertha IronsHigh ball speeds and increased spin robustness from our industry-leading A.I Flash Face Cup. Ball speed is further enhanced by our 360 Face Cup that flexes and releases at impact.Improved Turf Interaction From Legendary Big Bertha ShapingA club profile that’s engineered to give you more confidence over the ball with noticeably wider soles. For an easy launch, lower spin, and a straighter flight, we’ve added more offset into the head.Easy Launch From Our Visible Tungsten Energy CoreNow you can get higher launch conditions through the set. We’ve added a significant amount of custom tungsten weighted, so we can deepen the CG with extraordinary precision while still maintaining high ball speeds.Pure Feel From Urethane MicrospheresOur patented urethane microspheres comprehensively absorb unwanted vibration for exceptional feel, while also maintaining fast ball speeds.