The red button resets the roll band to the default setting, the first position. Useful if you have made an adjustment at the end of the list and want to return to the beginning - or if control unit and roll band are out of sync. But please be careful if you are traveling for example in Spandau and have 120 possible settings. This will be taken from the end you can over again cost a lot of time. Resetting the band accidently may cost you a lot of time!
Please use the red button to reset and enjoy it from the outside.