Siemens 3SU1050-4BN01-0AA0 Actuators and indicators, 22 mm, metal, shiny. Siemens 3SU1050-4BN01-0AA0 is the exact printed commercial reference for a pilot and control device in the SIRIUS ACT 3SU range. Siemens' official product description is: RONIS key-operated switch, 22 mm, round, metal, shiny, lock number SB30, with 2 keys, 3 switch positions I-O<II, left latching, right momentary contact type, actuating angle 2x45°, 10:30h/12h/13:30h, key removal O, possible special locks: SB31, 421, 455.