Wilson Staff Men's D100 Half and Half Golf Club Iron Set, Right Hand, Regular, Graphite, 3H 4-GW Wilson Staff's D-100 family utilizes lightweight technology to increase distance by achieving faster ball speeds with the same swing effort 7% thinner iron face delivers faster ball speeds and unsurpassed distance Exoskeleton technology used with an undercut cavity allows 35% more mass to be moved to the sole, heel and toe areas for extreme forgiveness Optimized head proportions throughout the iron set deliver ideal launch angles, ball speeds and spin rates for each loft