Here is a thread on the Panther Review.
The Kaiser Panther with the wood joint has a phenolic combo (12.74mm tip)
as for the J&J J/B with the quit release joint it has a 13.32mm tip.
Hope this helps, if you need a bit more clearification, please let me know how I can help.
The Panther to me breaks even better and I can control it better than the J&J J/B, I like the hit better on it. I would suggest spend the $80 for the Panther rather than the $60 for the regular J&J J/B. Many of the members here sells them. I would Recommend Troy (KOINKID). Very easy guy to deal with. Or check out one of Rick's new J/B(Poolfool1957), they are some really sweet j/b for the price he is selling them at...