I collected a few of these a while back to play with... never ended up using any them...
They were all labeled K-64-KN so they were originally used/meant to be used in the CF-2 with a K703 horn. You likely already know but in case you don't, this is the exact same driver used in the K-63-KN (CF-3 and CF-4) it was just mated to a K603 horn in that assembly. Speaking of used/meant to be used... I am not fully aware of this guys past life/lives. I know what little I did with it and that the driver still test good but can't say with any certainty how new or used it actually is... just trying to be honest. Driver is dated Nov 4 1995
I have this currently listed on ebay for $130 shipped within the continental US (I would prefer not to ship internationally)
Side note: I actually have a CF-2 crossover lying around in the garage somewhere if some one might be interested in that too... no horn though
Edit: All of these have been sold off as of Feb 2018