The point is to show that people will swallow just about anything thrown to them be advertisers. The twistpad knob is but a magnet in a plastic wrapping. It costs less that a dollar to make and is sold for anything between 80 and up to more than two hundred US dollars! The statistical possibility of misplacing it, throwing it away by mistake, since it is detachable is high. One can still use to induction hob but, with considerable difficulty. (There instructions in the user manual and also a couple of videos in youtube).