The device (XS-00B) arrived properly packaged and with all parts.
However:
when connecting the battery, the engine started working immediately regardless of the position of the on/off switch.
After disassembly, I found that sometimes when turning on using the on/off switch, the engine sometimes turns on, sometimes not, and sometimes goes into slow rotation mode with increased heating.
I assume that it is an error in the bldc controller, that is, the pcb to which the battery is connected.
The battery can be charged via the attached rectifier and it works properly.
By the way, I am a M.Sc. electrical engineer and I consider myself a qualified person.
If you would send me the PCB board with the controller, I would replace it myself (solder the connecting wires).
I did not check the function of the device as pump.
Miloš 
Olsen 
