accufitgolf There used to be a difference, the reason they added the "U". Nowadays, they no longer need to add that, because of the universal change in tips. It's probably why older Ping irons are so hard to pull shafts from; the shafts were 'jammed' in + epoxied. (same with other brand older irons, but hardly anyone re-shafts them today, or uses them, like they do Ping. )