ETA - unexpected shock

[WatchMaker]

I've lost count of the number of ETA movements I've worked on ... but all of them have used the Incabloc shock system. If I look on ranfft or google images then, again, all I see are Incabloc.

I'm currently servicing a movement that, whilst not having any ID in the usual spot under the balance, I'm almost certain is an ETA 2622 ... and yet this uses a Kif Ultraflex system.

So I'm now intrigued ... why would ETA chose to use a different shock system on this particular movement? [And note that other pictures of ETA 2622's I've found use the Incabloc system as expected].

Any insight or comments greatly appreciated!

 

Edited June 21, 2019 by WatchMaker