The knob for Essedue 300 Eco and all Essedue vertical slicers is the graduated thickness-adjustment control fitted to the front panel of the machine, the part you turn to set how thick each slice will be cut. It is designed to fit the 300 Eco model as well as, more generally, every vertical slicer in the Essedue range, which makes it a practical choice when you are not completely sure of the exact model code of your machine. With daily use this knob wears out: the collar can loosen, the graduated numbers can rub off until they are no longer readable, or the plastic body can crack or break after knocks and repeated stress. Once the thickness setting becomes imprecise, the knob turns without engaging, or visible cracks appear on the body, it is time to replace it with this compatible spare part, restoring the slicer's original cutting precision.