What the breaking capacities mean for your panel
The Siemens 3VA2010-5KP32-0KC0 is a 3-pole SENTRON molded case circuit breaker rated for line protection, carrying 100 A continuous current (Iu) through the full 40–50 °C range before it begins to derate — 96.25 A at 55 °C, 92.5 A at 60 °C, 88.75 A at 65 °C, and 85 A at 70 °C. The headline number is the interrupting capacity: 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 3.4 kA at 690 V. Those figures tell you this breaker can sit at the main or a high-fault subfeed in a 480 V panel where available fault current pushes past 100 kA — the 121 kA at 440 V covers that scenario cleanly. The ETU850 electronic trip unit handles the protection curve. It supports communication (the listing confirms a communication function) and includes a voltage trigger input.
That depth is the body only — allow clearance for the shunt trip wiring and the communication connection at the front.