The M100 Stopswitch is a simple inductive shaft speed monitoring device. The self-contained unit has a single set point, which signals when the shaft has stopped rotating. It can be used for process control, motion detection and stopped shaft indication. An inductive sensing device located in the nose of the M100 enclosure will detect a metal target. This target can be an existing bolt head or device attached to a shaft. The M100 Stopswitch requires no calibration and provides an output when the shaft has stopped rotating.