Siemens 3SE5122-0CH02 Enclosure width 56 mm. Siemens 3SE5122-0CH02 is the exact printed commercial reference for a limit or safety switch in the SIRIUS 3SE range. Siemens' official product description is: position switch metal enclosure 56 mm wide device connection 3x (M20x 1.5) 1 NO/1 NC quick action contacts part-turn actuator right/left adjustable, with metal lever 27 mm long and stainless steel roller 19 mm.