That a power supply is not supplied, is to be welcomed because of the mobile phone is already doing, that you can use without any problems here; it is so far contained nothing superfluous. Beware, the loading means DK30 dock, connected to a USB hub without specially designed for 1.5A port, worked with me to the dock not while charging at direct connection of the Xperia Z Ultra to the same hub works very well!
In order to stabilize the dock while you turn the smartphone or unpluging, double-sided tape or a power strip is recommended.
However, I think that 35 euros are actually completely covered for that bit of material and technology. If it were not nervous so (and I would not do this to worry about the life of the unit), every day the waterproof cover (which I wanted to have quite) to pfriemeln from the USB port of the Xperia Z Ultra to load it, I had the equipment not bought.