I bought this to go with the Elektron:Model Samples (As the Ripcord I bought was the right voltage, but did not fit)
This definitely does the trick, although I feel it can sometimes fall out a bit, so the connection does not seem quite stable. Obviously just for jamming on the couch with the model samples or when travelling, this is not a big issue, however I would not rely on this for live usage. (without adding some gaffa to secure it). (I think this is mostly an issue with the port on the M:S, so maybe filing down the edges on the plastic bit would give it a better fit.)
All in all it is a nifty thing to have, the one I got for my Korg Volca fits perfectly without any issues.