Wilson Staff C200 Irons Steel 8-Piece Set 4-PW,GW KBS Tour 90 Regular Right Set composition: 4 iron gap wedge Flex face technology minimizes contact points between the thin face and club head for maximum face flex on all strikes Power holes around the perimeter of the club head allow the face to flex on impact for extreme distance TE031 urethane fills the power holes to improve sound and feel