PowerBilt Grand Slam Oversize Irons feature: Oversize heads with cavity-back design produce a very large sweet spot and maximum forgiveness on off-center hits Stainless steel clubheads for improved feel and increased durability. Heel-toe perimeter weighting for increased consistency Dual relief sole reduces turf drag. Pyramid scoring alignment feature on the club face for more consistent and accurate alignment. Progressive offset design makes the longer irons easier to hit and the shorter irons more accurate.