Siemens 3SE5122-0PA00-1CA0 Enclosure width 56 mm. Siemens 3SE5122-0PA00-1CA0 is the exact printed commercial reference for a limit or safety switch in the SIRIUS 3SE range. Siemens' official product description is: Basic switch for position switch 3SE5112 Metal enclosure 56 mm increased corrosion protection (increased corrosion protection) 3x (M20x 1.5) 2 NO/1 NC slow-action contacts without actuator head.