Auxiliary switch, side-mounted, 1 NC + 1 NO, Left: 41/42, 53/54, Right: 21/22, 33/34, current path: 1 NO, 1 NC, screw connection, for contactors 3RT2.1. SIRIUS 3RH29 auxiliary switch for expanding auxiliary contacts in the control circuit. The side-mountable auxiliary switches 3RH29 can be mounted on the 3RT contactors without tools, regardless of size. The auxiliary switches 3RH19/3RH29 are available as front or side-mounted variants, with up to four instant switching normally closed or up to two early switching normally open contacts. The auxiliary switches can be designed as forcibly guided contact elements in auxiliary contactors 3RH or as mirror contacts in power contactors 3RT. They are available with screw connections and spring-loaded connections. Simple, efficient, always up to date - the SIRIUS system modular concept.