The Siemens 3VA9138-0CK12 is a SENTRON Max-Flex remote operating kit — a Bowden wire actuator assembly that lets you open or close a 3VA5 125 molded-case circuit breaker from a panel door or remote location. The kit includes a steel handle with an epoxy sheath rated NEMA 1, 3R, and 12, and a 0.9 m (36 inch) Bowden cable. That NEMA 12 rating means it's sealed against dust and dripping liquids, so it can live on the outside of a non-washdown enclosure without a separate weather hood.
Lifecycle stage is current.
Integration is straightforward: the Bowden cable routes from the breaker's switching mechanism through a gland plate or knockout to the handle mounted on the enclosure door. The 0.9 m cable length covers most single-door panel depths; for deeper cabinets you'd need a longer cable or a different actuator variant. The handle's NEMA 1/3R/12 rating lets it sit on an outdoor or indoor enclosure surface without additional sealing — just a standard panel cutout and four mounting screws.