Siemens 3SE5122-0KA00-1CA0 Enclosure width 56 mm. Siemens 3SE5122-0KA00-1CA0 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 Device connection 3 x (M20 x 1.5) 1 NO/2 NC slow-action contacts without actuator head.