The device has a hazardous design flaw: The entire housing is made of plastic. If now is heated during use of the inner container of the fryer, containing the oil, although the plastic housing remains pleasantly "cool" (you can safely handle); but it expands apparently total and the result is that the cover is no longer locked properly. Consequence: suddenly jumps during the frying process ever on the cover. This happens without warning!
So you can
1. the fryer do not leave them unattended (is not recommended in any case when working with hot oil / shortening, one would perhaps be able to accept at the geschloossenen system) and
2. could have a serious personal injury.
