Wilson Di6 Irons. Wilson Staff engineers have designed Di6 irons with progressive and perimeter weighting which moves weight away from the face, creating a massively forgiving surface. Slight offset helps square the face at impact, while an elastomeric dampening layer cures vibration from off-centre hits. Weight moves from the toe in the long irons to the heel in the short irons to maximize distance and playability. Taper-Tech Steel Shafts - a progressive tip design transitions from high tip flexibility in the long irons for higher launch, to a stiff tip in the mid to short irons for a lower launch and maximum control.