Originally Posted by
Crankycrank
I'm no expert on these but I have seen the two groove versions selling on multiple on-line sites. Just saw a used one on Ebay with the 3 grooves so possibly as you mentioned the one you received is just an updated version but I would contact Park directly as they would be the best place to answer your question.
I have already contacted ParkTool with this very question.
In their answer they did not provide any comment on the number of grooves or production changes. They only stated that there should be four spring rings, not two. They asked me for my address to send me two extra spring rings.
Frankly, their answer makes zero sense to me. The most outer grooves of the tool do not really need spring rings. They are intended for the retaining rings (included with the tool in a separate bag), if the user wants to
permanently install the taps onto the handles. Only the inner grooves (the ones that end up under the taps) need spring rings. So, the three-grooves-per-handle version of the tool needs four spring rings total, and the two-grooves-per-handle version needs two spring rings total. I.e. my tool is OK with two rings, it is just that someone at the assembly line managed to install the rings incorrectly.
Basically, it appears that whoever answered my question at ParkTool just didn't bother to fully understand the issue.