I had never heard of them so I Googled.
They seem to be German and look like high quality stuff.
I assume you are interested in the single circuit plug connectors that look a lot like a shortened version of a banana plug.
They look like they come in several colors, which would be real handy for circuit ID.
One thing I wonder is if they are compatible with banana plugs?
I don't know if anyone on this side of the pond distributes them. You may want to try Mouser or Digikey.
Rod