Amati Kraslice currently makes very high quality wood clarinets, and is famous for their Full Boehm instruments.
However, back in the day, apparently, they weren't as good as they were now.
Here is an example of an older Amati, from somewhere between 1960 and 1980.
This must have been during the Soviet Era.
As I remember, the quality of the instrument was probably a little better than your typical Soviet instrument, though definitely not the best.
It is made out of some kind of composite, probably not hard rubber, but I can't be sure.