The Siemens 3VA9877-0LB11 is a locking provision for the handle accessory on 3-pole 3VA57/58/59 and 3VA67/68/69 circuit breakers. This is a panel-mount part that secures the breaker handle position — useful for lockout/tagout procedures where you need to physically prevent the breaker from being switched on during maintenance. It ships as a single piece, so order one per breaker position.
Sourcing
Product class B means return is restricted; coordinate with your Siemens partner if a return situation arises.