Siemens 3SE5122-0LA00-1CA0 Enclosure width 56 mm. Siemens 3SE5122-0LA00-1CA0 is the exact printed commercial reference for a limit or safety switch in the SIRIUS 3SE range. Siemens' official product description is: Basic switch with increased corrosion protection Position switch 3SE51 Metal enclosure 56 mm 1 NO/2 NC quick action contacts without actuator head.