The Siemens SENTRON 5SP3763-1 is a selective miniature circuit breaker (MCB) — three poles, rated 63 A at 400 VAC, 50 Hz, with a Class E trip curve. That's the spec that matters for selectivity studies: you need this breaker upstream of lower-rated downstream devices to clear a fault before they pop. This isn't a standard thermal-magnetic MCB. The Class E characteristic is a selective (delayed) trip — it holds through short-duration overcurrents so downstream breakers can clear first. That makes it a main or feeder breaker in a distribution panel, not a branch-circuit protector. The 63 A rating and 3-pole construction suit it for three-phase residential or light commercial infrastructure mains, as noted in the suitability listing.
That's about 108 mm of rail space. It can also be mounted on a busbar or with screw fixing using accessories. The 20 000 mechanical switching cycles typical service life is solid for a main breaker that sees infrequent operation. Shock resistance is 30 g, 3 impacts at 11 ms duration; vibration resistance is 2 g, 20 frequency cycles from 5 to 150 Hz per IEC 60068-2-6. That covers most industrial environments short of heavy rotating equipment with persistent imbalance.