The Schneider Electric MGNA9 is a neutral rail kit — a circuit breaker accessory designed for mounting inside distribution panels to provide a dedicated neutral termination point for branch circuits.
Mounts inside the panel enclosure alongside the main breaker or load center. The neutral rail accepts the neutral conductors from outgoing branch circuits and ties them to the system neutral bus. Typical deployment is in commercial or industrial distribution boards where a separate neutral bar is needed for code compliance or circuit organization.