Transformer / power supply unit is included. There is a rail part where the control unit is also plugged in, then plug in the connection from the power supply unit and then it runs.
The best thing to do is to contact our customer service directly at https://helpcenter.galaxus.ch/hc/de/requests/new. Your request can then be examined individually.
I returned the system, not because of the quality, but because it only runs on batteries in this form. I thought that was unecological and an additional power supply unit is too expensive in relation to the price of the racetrack. The range is compatible with the Carrera tracks.
I ordered another, somewhat more expensive offer with a power supply unit.