Meeting international standards such as UL, CSA, CE, EN 61058-1, and RoHS environmental requirements, the Series 51 stop switches utilize an industry standard 16mm mounting hole. Suitable for medical diagnostic equipment, handheld pendants and devices, machine and process control and instrumentation amongst others, the compact design results in a slight back-panel-depth of just 18.8mm. The visible actuation status ring enhances ease-of-operation by providing quick indication of the actuated state at all times. EAO Corporation