Big Bertha OS Irons promote more distance in an entirely new way led by extraordinary light and strong Exo Cage that allows us to strategically position weight to increase forgiveness and helps our industry leading next generation 360 Face Cup produce even faster ball speeds and more distance. Features + DetailsMore Forgiveness and Ball Speed from New Exo Cage TechnologyThe uniquely light and strong design of the Exo Cage allows more weight to be positioned in strategic locations to increase forgiveness while also helping our next generation 360 Face Cup technology to function more efficiently.Even More Ball Speed from Next Gen 360 Face CupNext generation 360 Face Cup technology elevates clubface COR closer to the USGA limit to produce even faster ball speeds and more distance.Higher Launch for Longer Carry from Tungsten Loaded Standing WaveTungsten Loaded Standing Wave technology in the sole lowers the center of gravity to promote a higher launch angle for longer carry and more ball speed on hits low on the face.Progressive Center of Gravity for Increased ControlProgressive Center of Gravity technology entails moving the CG location progressively lower in each head from the highest lofted to the lowest lofted promoting higher launch and long carry in the long irons and increased control in the short irons.Women’s and Senior ModelsLighter in overall weight with more loft to promote faster ball speed and higher launch angle to make it easy to get the ball in the air.Specifications: Name Loft Availability Standard Length Lie Offset Swing Weight #4 20.5° RH/LH 39.125" 60.50° 0.260 D0 #5 23° RH/LH 38.50" 61.25° 0.240 D0 #6 26° RH/LH 37.875" 62.00° 0.220 D0 #7 30° RH/LH 37.25" 62.50° 0.200 D0 #8 34.5° RH/LH 36.625" 63.00° 0.175 D0 #9 39° RH/LH 36.00" 63.50° 0.150 D0 PW 44° RH/LH 35.75" 64.00° 0.125 D0 AW 49° RH/LH 35.50" 64.00° 0.100 D0 SW 54° RH/LH 35.25" 64.00° 0.100 D0 UST Mamiya Recoil ES 460 Graphite Manufacturer Flex Shaft Weight Torque Kickpoint UST Light 64 mid low UST Reg 65 mid low UST Stiff 68 mid low