Today I got the Mumbi FM transmitter and debugged directly. Unfortunately, I realized that is the range of the remote deficient. The range is only about 5 cm and you have to point the remote control directly in front of the infrared LED. One is unfortunately forced to use the remote control, as you can select the folder directly only with the remote control.
Otherwise, it's a good solution for radios without USB port.
Only 1 star because of poor or inadequate coverage of the remote control and thus resulting restriction of functions.