The Bently Nevada 3500/50 133388-02 is a 2-channel speed and keyphasor monitoring module for the 3500 machinery protection system, designed to deliver high-precision rotational speed measurement, phase reference signal acquisition, and reliable overspeed protection for critical rotating industrial equipment such as turbines, compressors, pumps and motors, with programmable speed thresholds, configurable redundant voting logic, integrated relay outputs and standard industrial communication capabilities for enhanced equipment operational safety and condition monitoring.