The adapter works fine but the kind of "probe" which opens the cassette VHS-C component (the one that masks the band) is not the right place and is very fragile. If we are not careful, it is placed on the outside of the cassette and not under the door, and when the case is closed, the shutter does not open and the probe will likely case (I avoided this, fortunately!)
So to use product with great care, ensuring that the probe is famous as part of the mini-cassette before closing!