Big Bertha B21 Irons The First Big Bertha Iron Designed With A.I. You're looking for more distance, and the Big Bertha B21 Irons are here to give it to you. In fact, we've designed our legendary Big Bertha shaping with a NEW formula for distance and forgiveness...any way swing it. Features & Benefits Fast Ball Speeds From The First A.I. Designed Big Bertha Irons High ball speeds and increased spin robustness from our industry-leading A.I Flash Face Cup. Ball speed is further enhanced by our 360