His duty ...

At Level 2, you can keep everything nice and warm. The warming per se, however, take a little. Especially with mash some time has yet to be scheduled. Taking this into account, however, the time is not a problem.
Another point to bear in mind it applies to: Unit will not turn itself off. If we had even forget to switch off, then we got our mistake with only when the water was almost completely evaporated and caused by the heat noise. Does course in return that you can keep warm long.

All in allem- cheaper, functional Babykostwärmer.