EGO 50.57071.010 Simmerstat 13A, 240v work by means of a bi-metal strip that flexes under temperature to make a circuit switching on and off depending on the knob position. The shaft size is 6mm and the mounting is via 2 x M4 screws. Knobs and bezels to suit are available.
These are used to control the temperature of equipment such as Bain-Maries and hot cupboards. They control the temperature without any direct temperature measurement.
P1 – Live
P2 – Neutral
2 & 4 are the load (not polarity dependent)