The Siemens SIRIUS 3RU6900-1B is a cable release with holder designed for remote RESET actuation of 3RU6 overload relays in sizes S00 and S0. At 400 mm long, it reaches from a panel door or enclosure front to the relay's reset mechanism without needing to open the enclosure — useful for production lines where the starter is inside a sealed cabinet and the operator needs to clear a trip from outside.
Mounting diameter is 6.5 mm, which matches the standard reset-stem bore on the 3RU6 relay face. The cable routes through a panel gland or knockout; the holder snaps onto the relay's front bezel. No special tooling — just a 6.5 mm hole in the door or subpanel and clearance for the cable bend radius.
The SIRIUS brand designation confirms it is part of Siemens' modular motor-management system, meaning the release shares the same mechanical interface as the 3RU6 family.