Siemens 3SE5212-0BF10 Enclosure width 31 mm acc. to EN 50047. Siemens 3SE5212-0BF10 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 according to DIN EN 50047, 31 mm device connection 1 x (M20 x 1.5) 1 NO/1 NC slow-action contacts angular roller plunger with plastic roller 13 mm.