Callaway X Hot N14 Irons Iron Set Deep Undercut Cavity: This cavity allows the face to flex and rebound at a higher rate increasing the ballspeed resulting in consistently longer iron shots Perimeter Weighting: Lower sweet spot, higher launch angles and more forgiveness are all the result of the perimeter weighting in these irons The sweet spot lower in the clubhead resulting in faster ballspeeds Higher launch angles and more forgiveness