Exactly what is says it is! It has the MSX logo on it, however, when I tried it on my TurboR it did nothing. I guess that it works for the HX10 only, but who knows?
Bas: is it only a ROM or does it have more electronics in it? IF it's only a ROM, it would be interesting to examine the code, maybe. (So, a dump would be nice to investigate.)
The thing is that it is now much more affordable to buy items in sterling pounds 'cause its exchange ration with the euro is almost 1:1. We could buy out the whole UK, it is on sale now!