The potentiometer grinding track is embedded in a blue plastic housing and is picked up by precious metal grinders. The back of the housing is sealed dust-tight with a cover. The stainless steel drive shaft is mounted in bushings. Up to 3 potentiometer levels can be lined up one behind the other with a common wiper shaft. The levels can be adjusted against each other. Delivery is possible with or without mechanical stops. The PP 27 potentiometers are used as setpoint adjusters and as actual value and reference potentiometers in control and measuring circuits.