It is in some applications to compete with Kirschkernkissen, in the long run you need anyway maybe both.
When our HK 30 heating pad I can not damage through excessive temperature me. When Kirschkernkissen we have to be careful every time after heating, it is not too hot.
Since I in ear problems no particular success with ASA, ACC, ibuprofen, nasal drops, ear drops had recently, were really hot onion bag on the ear, the active agent. At first I could almost scalded me here also. But then also the heating pad was extending the application useful and necessary.
I have again compared: HK30 and HK35 successors have both 100 watts.
The only novelty at HK35 is a Turbo heating, but which I can not evaluate.
The automatic switch-off is from 30 HK (and HK 25), but not in HK 20 available.
Before purchasing you can get the manual in PDF format and is again something set it at beurer.com under Service.
(The "Beurer HK 30" there are currently less than 5 different items names at Amazon.com,
the "Beurer HK 35" different under Article 8 names)