The Tour I(z) ball is an old ball on WGT. They have since been replaced with the Callaway Hex Chrome or Callaway Chrome soft.
The chrome soft (L33) took over for the Callaway Tour I(s) and the Hex Chrome (L35) took over for the Tour I(z).
I see you are playing the L39 (love it) which is the yellow version of the L35 which is the same ball as the Tour I(z) you talk about. Just the typical model name change in the game for a ball with the same specs as before.