The KOBOLD level switch of model NEK is a complete functional unit which is specially designed for monitoring conductive liquids under extreme conditions. Due to the de-sign without any moving or protruding parts, the switches are very suitable for monitoring critical media with, for example, solid content, negligible density or high viscosity. The double-thread allows a variety of installations. The length of the shaft can be extended by attaching an additional protective tube. The instruments operate on the conductive principle of measurement. The conductive medium touches both electrodes causing a negligible alternating current to flow; the output state changes.