Operation is simple: press the hidden behind the flap switch long a = in automatic mode, ie the sole turns on in 5-minute intervals and from. Press the switch again briefly = a permanently high, again briefly press with low heat setting. Press the switch a third time shortly = automatic mode again. Switch long press of =.
The heat output is in mode "high" noticeable and pleasant, the temperature, I have not measured, but the specified 50 degrees in the mode "high" achieved the deposit to my mind not, but holds the sole even when standing in cold weather to body heat.
A limitation is to say that the deposit does not constitute a well-molded footbed, ie. Longer Running is rather less pleasant, but on the run you generally always warm feet, the application range of this deposit is clearly prolonged standing, for example, at the Christmas market. To mute the sole back on or switch, you must insert the course half pry out of the shoe, which depending on the shoe can be a bit fiddly and is recommended outdoors rather less.
Anyway, a good solution for really cold days when only a little stroll or a long time is.