The Siemens 3SF5816-0A. is an AS-Interface enclosure for command devices — a plastic, round 22 mm housing with a gray top part that accommodates up to 6 control points. It is not an emergency stop device and has no positive opening mechanism, so it is suited for standard signaling and operator input stations, not safety-rated stop circuits. The 22 mm mounting diameter and round installation opening match the standard panel cutout for pushbuttons and pilot lights, and the enclosure can be fastened vertically or horizontally depending on the panel layout.
The enclosure has no pre-wired strip terminal in the delivery state, so wiring is done on-site to the AS-Interface bus connection. No light source or front ring is included; these are separate add-ons if the application requires illumination or a bezel.