Wilson staff d300 irons ndash steel in terms of looks and performance these clubs are considered by wilson to be the best theyrsquove ever produced they improve upon the factors that made the award winning d200 family renowned using cutting edge ldquopower holesrdquo filled with te031 urethane which controls vibration with improved length and spacing the thickness of the wall has been changed strategically to provide for additional space for the face to flex upon impact wilson is