The Siemens SENTRON 3VA2010-5HN36-0HH0 is a 3-pole molded case circuit breaker (MCCB) rated for 100 A continuous current with no derating across the full 40 °C to 70 °C operating range — meaning it holds its full 100 A rating even in a hot panel or enclosure without needing a size-up. Breaking capacity is 187 kA at 240 VAC, stepping down to 121 kA at 415 V and 440 V, then 75.6 kA at 500 V, and 3 kA at 690 V — the curve tells you this breaker has the interrupting muscle for high-fault installations at low voltage, but at 690 V it's essentially a load-break switch, not a fault-interrupting device. Designed as line protection (not feeder or motor protection), this MCCB sits at the service entrance or main distribution point in a panel, sized for a 100 A bus.
The basic switch assembly is order code 3VA20105HN360AA0 — if you ever need to replace just the switching mechanism, that's the service part number.