Even better, it's a very common headphone connector....well, it used to be, back in the errrrr 70's? Its a so called "Würfelstecker", a special variant of a DIN connector especially for headphones. Wiki (in German) Adapters are available... adapter
Must be. Technical German is always an explanation of what the thing in question does... /goes off to look for examples in a patent spec
If you clicked through, then you would know it is meant to be a "Spielwürfel", which is a normal gaming dice. And it is Würfelstecker because the pins look like the 5 dots on the gaming dice for number 5 (obviously).
Just "Cube" really (Würfel) In Dutch it's a "Dobbelsteen", a stone to play "dobbelen" with. Dobbelen again refers to any dice game, which still doesn't say anything about the stone