The connection is simple (MIDI IN MIDI OUT cable on the synth), and if you make a mistake, you can always check the connection by playing a few notes: the LED "in" should flash to receiving balanced by the cable.
The cables are long (3m).
With this interface, I can control the synth sounds from the PC without any perceptible lag, and I can record keyboard notes in the PC sequencer.
But as soon as I turn on the effects in the MIDI exchange (aftertouch for example), I lose communication: I have to disconnect / reconnect the USB.
I tested under Android 4.0.4 on my shelf, it works unless there is a max lag when using the master keyboard synth with synthsoft (surprising, but suddenly This is not very usable).
With my phone under 4.4.4, it works poorly; I get the notes but oddly apps work (loss of sound, keys locked, ...) as if the messages exchanged were corrupt.
So in summary, this product should be used with a sequencer (but I have doubts about the robustness of operation), and only for the raw scores without further control.
Anyway, this is disappointing for me ...
In the end, I bought the Roland USB MIDI Interface UM-ONE-MK2 works perfectly.