Siemens 3RH2911-2HA10 auxiliary switch, on the front, 1 NO, .3/.4, --/--, --/--, --/--, current path: 1 NO. Siemens 3RH2911-2HA10 is the exact printed commercial reference for a contactor relay / accessory accessory in the SIRIUS 3RH Contactor Relays range. Siemens' official product description is: auxiliary switch, on the front, 1 NO, .3/.4, --/--, --/--, --/--, current path: 1 NO, --, --, --, spring-loaded terminal, for contactors 3RT2 and contactor relays 3RH2.