[Premium-Rx] Rohde Schwarz FK859 Antenna Coupler?

[W2HX]

Hi friends and especially friends in Germany,

I saw the following image on a website of an R&S antenna coupler I believe the model number is FK859.  It looks like it was present at the Friedrichshafen hamfest in 2016. I am interested in learning more about this coupler and thought that perhaps some of these have found their way into amateur hands in Germany (or elsewhere of course).

I am looking for any information on this, primarily interface details of the circular connector. And secondarily any other maintenance or technical information on it.  I know there are two on ebay right now but the seller has no information on them.

http://w2hx.com/x/RohdeSchwarz/FK859.jpg

Does anyone on the list have any contacts within R&S? 
Please feel free to forward onto any friends you have that might know something about this coupler.

Thanks!
73 Eugene W2HX