The Siemens 5SJ6314-7 is a 3-pole SENTRON miniature circuit breaker with a C-curve tripping characteristic, rated at 0.3 A at 400 V AC. The 0.3 A rating is unusually low for a 3-pole MCB — this is a fine-current branch protector, not a feeder breaker. It fits applications like control transformer primaries, signal power supplies, or very small resistive loads where a standard 1 A or higher breaker would not provide adequate overcurrent discrimination.
Occupies 3 width units (roughly 54 mm). Touch protection is built in (finger-safe terminals when wired).